Progress Thread What To Do With My Frankenstein

[Marcolivier]

I picked-up a 1977 mustang 2 with clean paint and a 302 a few weeks ago. It has almost no rust and it is a blast. It was overhauled in 1994 with a rebuilt engin, new paint, bushings and some mods. This was originally a 4 cylinder car. The 302 is from a 1978 and is modded with cam, intake, exhaust, high compression pistons, bigger valves and headers. The tranny is a 1989 5 speed with 2 gears from the 4 cyl engin in a 1978 manual bell housing and a short shifter. The differential is supposedly a 8.8 modified with a 9 inch gear kit that locks it up if I turn more than just a little. Better, wider tires and a pretty stiff suspension were all included.

Overall, the mix makes for a loud and fun ride, but for some reason I cannot explain, I would like to accelerate rly fast with it and maybe turn a little too, lol. Brakes are pretty bad also.

To sum things up, my question is, what can I run to make this thing rly go.

The motor has 10k miles on it since its last overhaul and I was thinking of a strocker kit, heads and maybe a supercharger if I could find one that fits. Can crate engins bolt up to the 1978 motor mounts and transmission bell housing, intake and exhaust?

Now If I mod the existing engin, what kind of hp can the rest of the drivetrain handle?

I think my main concern with suspension right now is getting a posi diff in there. I am nervous about taking any kind of curves with the diff I have now. Are there any options you could recommend?

My idle is kind of rough and I think part of my bad braking is coming from bad vaccum. Also tiny front discs and rear drums don't help. Is there a solution other than brigning up the Idle? The sound is rly cool at this Idle.

My tranny has 2 flaws, it doesn't downshift to 3rd due to a synchro problem and the first gear is too small. Its basically a 4 speed. Is there a better transmission to swap instead of the 1989? I am also thinking of just changing to a bigger diff, that would solved my locked diff issue and my small gear issue. Are there good options out there?

This is not a drag project or a show project, it doesn't have to be perfect, its just for fun.

 

[Bullitt347]

Mustang 2's came with 8" rear ends. You could put an 8.8" rear in it, that would take all of the power you could make if built right. Rear disc conversion is possible as well. All of this modification stuff is possible dependinng on budget.

 

[Marcolivier]

Just took abetter pic.

 

[MustangIIMatt]

I picked-up a 1977 mustang 2 with clean paint and a 302 a few weeks ago. It has almost no rust and it is a blast. It was overhauled in 1994 with a rebuilt engin, new paint, bushings and some mods. This was originally a 4 cylinder car. The 302 is from a 1978 and is modded with cam, intake, exhaust, high compression pistons, bigger valves and headers. The tranny is a 1989 5 speed with 2 gears from the 4 cyl engin in a 1978 manual bell housing and a short shifter. The differential is supposedly a 8.8 modified with a 9 inch gear kit that locks it up if I turn more than just a little. Better, wider tires and a pretty stiff suspension were all included.

Overall, the mix makes for a loud and fun ride, but for some reason I cannot explain, I would like to accelerate rly fast with it and maybe turn a little too, lol. Brakes are pretty bad also.

To sum things up, my question is, what can I run to make this thing rly go.

The motor has 10k miles on it since its last overhaul and I was thinking of a strocker kit, heads and maybe a supercharger if I could find one that fits. Can crate engins bolt up to the 1978 motor mounts and transmission bell housing, intake and exhaust?

Now If I mod the existing engin, what kind of hp can the rest of the drivetrain handle?

I think my main concern with suspension right now is getting a posi diff in there. I am nervous about taking any kind of curves with the diff I have now. Are there any options you could recommend?

My idle is kind of rough and I think part of my bad braking is coming from bad vaccum. Also tiny front discs and rear drums don't help. Is there a solution other than brigning up the Idle? The sound is rly cool at this Idle.

My tranny has 2 flaws, it doesn't downshift to 3rd due to a synchro problem and the first gear is too small. Its basically a 4 speed. Is there a better transmission to swap instead of the 1989? I am also thinking of just changing to a bigger diff, that would solved my locked diff issue and my small gear issue. Are there good options out there?

This is not a drag project or a show project, it doesn't have to be perfect, its just for fun.

Allright, been waiting to reply to this until I got to where I could do so from a computer instead of my phone or tablet, as there's a lot here.

First off, congrats. You've joined the rarest club of the Mustang world in buying a II. Haters are gonna hate, but hell, that's a big part of the fun of owning one.

The "tranny is a 1989 5 speed with 2 gears from the 4 cyl engin in a 1978 manual bell housing and a short shifter" probably means they just used a 2.3L fox-body Mustang T5. The biggest differences between the 2.3 and 5.0 T5s is that the first two gears were a little steeper on the 2.3L cars, and the input shaft had a smaller diameter. The only way to know for sure what you've got is going to be to tear it down, as it always is when you buy someone else's project (I'm in the same boat, I can verify what's in my car because I've torn certain things down when checking to see what I really had and to verify certain things were done correctly).

On the diff, I'm not sure what they/you mean by "a 8.8 modified with a 9 inch gear kit that locks it up if I turn more than just a little." The 8.8 and 9" are completely different animals and don't share compatible parts. The 8.8 is a C-clip equipped axle with a bolt-on rear cover. The 9", like the 8" that was likely stock in your II (though as a factory 2.3 car, it could've had the 6.75) is a rear-end that's guts load from the front, and uses bearing retainers at the ends of the assembly to hold in the axles instead of c-clips. From your description, it SOUNDS like you may have a Detroit Locker in the rear end that's acting up (mine does after it sits for long periods of time). Check your fluid level, and then drive it to a big empty parking lot where you can do a few lazy, wide figure 8s slowly. If that IS what's going on, it should fix it. If not, you've got a spool, welded spider gears, or a problem back there, for any of the above, you'll need to tear it down to see what you're dealing with.

As far as what kind of HP the drivetrain can handle... that's going to be dependent on what said drivetrain actually is. Some pics will help, especially of any part/engineering numbers on the transmission (I can have one of the parts guys run them at the Ford counter at work, or even see if they'll let me back behind the counter for a minute to do it), pics of the diff (there are identifying characteristics of each of the diffs in the Ford family that will tell us/you at least WHICH axle you have), and some pics of the rear suspension. The biggest limiting factor in a II isn't usually powertrain. It's traction. These cars have no weight over the rear tires, and even with a bone-stock 302 pushing 139hp and less than 300ft/lbs of torque, they will shred the tires non-stop. I've got air shocks, a pinion snubber, and a helper spring on each side in the back of my car, and I still have to launch feather-soft to keep from spinning them, and catch back up at the other end of the track. Stumpy is going to have his traction bars available soon, and I'm on the list for a set to go with his subframe connectors and see if I can't finally get this thing to launch a little harder. Once traction issues are solved, the weak link then becomes either the transmission (manual cars) or the 8" diff (automatic cars).

As far as "bad vacuum", what RPM is your idle currently set at? Do you know the specs on the cam? These will dictate what advice myself and others could give on helping you out with vacuum for your brake booster. It could be as simple as "raise your idle speed" to as complicated as "here's a list of cars that have small electric vacuum pumps at the junkyard, what other parts you need, and how to hook it up".

 

[LILCBRA]

+1 to everything 74stang2togo says.

"I think my main concern with suspension right now is getting a posi diff in there. I am nervous about taking any kind of curves with the diff I have now."
It sounds like you may already have a "posi" rear end. You will be better served with a limited slip style differential. I personally have a Detroit Locker in mine, but you can probably go to something a little more "tame" and be happy with it. Lockers tend to have a "pop" or "snap" to them when they disengage while going around a curve/corner. Clutch style diffs don't tend to do that. I guess it just depends on what you want from your car in the long run.

As far as "I would like to accelerate rly fast with it...." changing your gears along with the differential change can give you the added acceleration. Since we don't know the specifics of your car, it's really hard to give you an idea where you can go from here. Again, my personal experience with my T5 equipped II, 3.55 gearing works well and gives you a pretty good balance, depending on your tire selection. I would like to say even a 3.73 gear would probably work very well, giving you a little more acceleration but sacrificing your cruising ability in comparison to the 3.55s. Tire and wheel size also play a role with this as I eluded to. The taller the tire, the more gearing you can probably tolerate, the shorter the tire the less gearing you would probably want. The best way to think about all of this is in comparison to a 10 speed bicycle. The smaller rear gear works well when you're taking off but doesn't really give you a lot of speed. The larger rear gear kinda sucks when getting started, but you can cruise fairly easily. So, in this example, the smaller gear is equivalent to something like a 4.11 where as the larger gear is equivalent to something like a 2.79. In the same respect, if your gearing was the same and the bicycle gears were equivalent to your tire size, the smaller gear, or smaller tire, will take off easily but will take some work to get going a decent speed. Likewise, the larger diameter gear/tire will take more grunt to get it moving but will move more easily the faster it is going. Confused yet? LOL!!

Anyway, I suppose first things first, find out what rear you actually have under your car. By the way you make it sound when you say that your 5 speed is basically a 4 speed is that you probably have 4.11 or higher gears. I'd concentrate on this first as it will more than likely be the most time consuming and expensive part of what you are looking to accomplish. If it has, let's say 4.11s, changing to 3.55s will regain the use of first gear. I ran 4.62s in my II for a little while and I am WAY happier with 3.55s.

As far as your brakes and vacuum and such, you can install a vacuum canister. They are designed to hold engine vacuum in reserve until you need it and are used in cases where your cam is aggressive enough that your engine doesn't produce a lot of vacuum. They aren't expensive really and fairly easy to install, you would just need some extra vacuum hose to make it work. Past that, there are a few different options if you were wanting to go to bigger brakes. This is one area of these cars that the aftermarket supplies a lot of options for, so it shouldn't be too big of a deal to find stuff for the front. The back is a little harder, but still not impossible. Again, first things first, make it work like it should and decide from there. It may just be that the booster isn't helping enough and once you're done with that you may be satisfied enough with the brakes to leave them alone for a while.

Another thing about your engine - do you know what all was installed in/on your engine? Cam specs, intake manifold, carb size, headers/manifolds, exhaust size and type, etc etc. The previous owner may not have known what the h**l they were doing and everything might be mis-matched enough to not work well together. Another thing that you may be satisfied with, depending on how they built this engine, could be as simple as an intake manifold change or correctly sizing the carburetor. Again, first on my list would be the rear end. Get that straighened out and I think everything else will seem minor afterward. Good luck!!!

 

[Marcolivier]

First off, you guys are awsome, this is rly helpfull.

I tried to get as much info as I could out of the previous owner, but this engin was built over 10 years ago and put into storage, he didn't know much about it and some of what he said didn't rly add up for me.

I took a few pics of the diff. I was also given some spear gears to go in it. Non locked ones. He said that the diff in the car was a 8.8 locking diff and that he bought it 1200$. He could of just been covering up a broken diff, I am not familiar enough to tell if it is working right. I can turn the steering wheel 3/4 of a full turn with no problem, passed that, it will not want to turn anymore. (Tire start screeching, slows the car way down).

I didn't see any numbers on the differential, were should I look?

This picture is just me bragging about my new toy.

This is the diff from the rear of the car

Left rear suspension viewed from the rear of the car

First time I see the gas pump...

Again, showing off, I think you guys can relate.

BTW I payed 7k Canadian for this thing, does that sound like a fair price? (5400 US approx)

I need to replace the electric fan, the stock one was added temporarely.

 

[Marcolivier]

I just read-up on Detroit differentials. When you are parking, does it just stay locked? I'm starting to think this is what I have.

 

[MustangIIMatt]

First off, you guys are awsome, this is rly helpfull.

I tried to get as much info as I could out of the previous owner, but this engin was built over 10 years ago and put into storage, he didn't know much about it and some of what he said didn't rly add up for me.

I took a few pics of the diff. I was also given some spear gears to go in it. Non locked ones. He said that the diff in the car was a 8.8 locking diff and that he bought it 1200$. He could of just been covering up a broken diff, I am not familiar enough to tell if it is working right. I can turn the steering wheel 3/4 of a full turn with no problem, passed that, it will not want to turn anymore. (Tire start screeching, slows the car way down).

I didn't see any numbers on the differential, were should I look?

This picture is just me bragging about my new toy.

This is the diff from the rear of the car

Left rear suspension viewed from the rear of the car

First time I see the gas pump...

Again, showing off, I think you guys can relate.

BTW I payed 7k Canadian for this thing, does that sound like a fair price? (5400 US approx)

I need to replace the electric fan, the stock one was added temporarely.

That diff appears to be a 9" (unless I'm mistaken, 8" diffs didn't have the vertical ribs yours has, haven't looked at mine in awhile, though I will probably be under it this weekend), DEFINITELY, not an 8.8" in any way, shape form or fashion. The rear suspension you've got is stock.

At $5400US, that's a clean II.

 

[Marcolivier]

Found this page: http://www.mustangii.org/decoder/axle/

Took a few more pics as best I could.

I'm thinking it's an 8 inch.

 

[LILCBRA]

Yeah, it's an 8", probably stock to the car although the gearing may have been changed. They are supposed to have a tag attached at one of the nuts holding the carrier into the housing. If it's missing, it's a good indication that it has been tampered with. By what you have said, my guess is someone probably put a spool in it. It's a cheap way to have both wheels spin while doing a burnout and helps with traction at a drag strip, but really makes the car undriveable under normal circumstances. You can get a rough idea of what gears it has by jacking the rear of the car into the air, marking the driveshaft, turn the wheels one revolution and count the revolutions of the driveshaft. Then you will at least have a good idea what ratio you have.

As for the Detroit rear staying locked while parked, I am pretty sure it is but I could be wrong. The way you describe your car doesn't sound like my Locker rear though. When my car turns, sometimes it will give a loud distinctive clunk when it disengages. That is where the Lockers aren't necessarily friendly on the street - many don't like that clunk. It doesn't sound like your car releases at all which is why I think someone installed a spool. If that is the case, and you don't mind the gear ratio, it really isn't that hard to put an open differential - or even a locker - into your housing. Your pinion depth is the big deal to set and that is already done. As for installing the ring gear, the hardest part is getting the contact patch right when testing your gear engagement. The good thing about 8"/9" rears is that can all be done on the bench. All you would really need is some spotting ink. There are a whole lot of installation write-ups out there to help you along. Here's one from mustangandfords.com, you can pick and choose where to begin and end.

http://www.mustangandfords.com/how-to/chassis-suspension/41618/

You could make it more driveable by just removing the ring gear and differential from the carrier and installing the non-locking differential that he has given you. I'm sure that would make a world of difference. If you tackle it yourself, just remember that the bolts holding the ring gear onto the differential will need Loc-Tite.

Just a couple of pics for reference.....

A spool:

A limited slip style differential, this one is a Ford Trac-Loc:

 

[jozsefsz]

That's a great article, I used it as a basis for rebuilding my 8" a few years ago (first one I'd ever done) and it came out perfect. No noise, clunks, etc. In addition to the spotting ink (diaper rash cream works just fine and adding a little zinc never hurt anyone), a dial indicator is pretty much the only special tool I needed for setting the backlash -- you WILL need to do that. A press or an oven at 250 degrees is all it took to mount the bearings. If you do end up needing to monkey with the pinion (you shouldn't) then crush sleeves are for the birds. Available spacers are much easier for a novice and you'll have a better outcome.

 

[Marcolivier]

What do you guys think of this thing?

https://m.summitracing.com/parts/dtl-912a616

After doing a little reading, sounds like my transmission, axles and driveshaft are good for 350 whp max.

Eaton diffs sound tough too.

Would the stock 1978 manual bellhousing hold 350whp?

 

[LILCBRA]

Your bell will more than likely be fine, unless there is some sort of flaw in it. I am still using a stock II bell with no problems behind my 302. I really don't have real world numbers, only Desktop Dyno ratings which estimate my 302 at about 360 fwhp. Some day maybe I'll get to take it to a dyno.....

I believe that is the Locker and what I have in my car. It's been a while since my purchase so Summit doesn't have the history online, but it certainly sounds like it. If it's what I have, I wouldn't foresee you having any problems with it as long as everything is installed correctly. And it works GREAT! You can save a little cash on your purchase if you decide to get it from Summit since they price match. Quick Performance offers the same differential for $475. Just contact Summit, reference and link them to Quick's website (or any other you may find if they are cheaper....) and they will match it.

http://www.quickperformance.com/Ford-8-Eaton-Truetrac-28-Spline-912A616_p_16013.html

They also offer a Trac-Lok differential that's a little less costly and I don't believe you will get the clunk associated with Lockers. I can't speak for them, but I would think it works just as well although you will have clutches to worry about in the long run.

http://www.quickperformance.com/Ford-8-Inch-Trac-Lok-Posi-Unit_p_16014.html

 

[Marcolivier]

Ty LILCBRA

I looked around trying to find part numbers. I found nothing that I could see on the block or transmission.

I did find out my carb was a holley 4780 with its choke tower grinded off.

4 to 1 style Exhaust headers have long 1 inch runners and couple to a 2 1/2 inch exhaust on each side. This feels appropriate for 350whp doesn't it?

My intake manifold is a Edelbrock performer 289. Not sure this will push the engin to 350rwhp?

Found distributor part numbers and such. I'll get back to this, but it all looks pretty big.

As for my brakes, they work much better if the engin is in gear than on Idle. Idle is around 700RPM and cam should be a solid roller tappet pro comp cam. With the valve clearances I was given, there are 2 "Magnum" serie cams that fit the bill.

As I put together a wish list for my drivetrain, I think the 2 biggest items are going to be aftermarket heads and a 347 stroker kit. I am wondering if the stock block will be an issue?

 

[Marcolivier]

My wheels are American Racing 15 x 7, 4 bolt wheels.

Front tires are 205/50R15 and there is litterally no room to grow.

Rear wheels are 225/60R15 and looks like they could be an inch wider. I keep reading that this size should rub, but look at the picture.

I don't see my mags on the american racing website, but I know of a place locally that can weld on a ring to make it wider. What do you think?

 

[MustangIIMatt]

I did find out my carb was a holley 4780 with its choke tower grinded off.

My intake manifold is a Edelbrock performer 289. Not sure this will push the engin to 350rwhp?

I'd find a different carb, and a Performer 289 isn't likely going to flow enough air for more than about 300 flywheel hp, getting 350 to the wheels (400+ at the flywheel) just isn't going to happen. I have the Edelbrock Performer RPM on mine, and with a LOT of work done to the heads, flattop pistons, 670cfm carb, headers, full MSD ignition, and a nice cam with roller rockers, it put down 267rwhp. Granted, that was through an automatic, but that's still just 350ish at the flywheel.

 

[Marcolivier]

Whats wrong with the 4780? I was thinking of getting a smaller accelerator pump cam for it. It squirts way to much, motor bogs down a little when I smash the gas.

They sell a jet kit I could play with too.

 

[MustangIIMatt]

Whats wrong with the 4780? I was thinking of getting a smaller accelerator pump cam for it. It squirts way to much, motor bogs down a little when I smash the gas.

They sell a jet kit I could play with too.

Whenever I buy something and the carburetor's had things epoxied shut, ground down, wired shut, etc. I always trash it and start off with something I can trust and tune correctly.

 

[jozsefsz]

That's also way too much carb for a naturally aspirated 302. You may never be able to tune the bog out - less accelerator pump shot may make it even worse. You'd probably go much quicker with a 600 cfm with vacuum secondaries. The removed choke horn tells me someone used it in a forced induction application. The power valve passages may also be drilled out, backfire check-valve removed, and other such butchery done to it (I know because I've done that for my turbo build). Any epoxy on the distribution block screws is a good hint too. So +1 to Mr. 74stang's comment on your carb. You'd probably be happier with something new and off the shelf. May improve your vacuum a bit too.

 

[great white]

Agree that an 4780 is too much carb for your particular engine.

I'm running a 4160 on my (essentially) stock 89 roller engine with an edlebrock rpm performer air gap.

While I haven't gotten it running yet, I have had similar combinations in the past running the 4160. You can get it to run well, but it takes a fair bit of work. It's saving grace on a smaller 8 is its vac secondaries. It's not exactly a combination for the "beginner" level wrenches though...

Most mild street engines are easier to set up in the 600 from range and still pull nice and hard from lower rpm.

You'd probably be happier with something in the 600-650 range for a driver.

350 rwhp isn't as easy as everyone makes it out to be either. Just "Bolt ons" aren't going to get you there.....