357w: would you do it again??

[General karthief]

Guess My H P !!! - The Dyno & 1/4 Mile Time Thread

UPDATE - FastDriver (26AUG13): After some recent interest in the forums, this thread is again active. Please feel free to add your own dyno, timeslip, and mods. The more details you can provide, the better. Posts without documentation will eventually be deleted. This thread exists to give...

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[Ragtop50]

While in some situations, depending on how you acquire the 351, it may come out cheaper than a dart, there is still all the swap parts you have to pay for.
There are no swap parts for a 347. You could literally bolt everything you own back on it.

I'd be curious on what everyone around here makes with their 351 builds, either quarter mile or rearwheel dyno.
Over the years other than on race cars, i've seen little proof it's worth the effort.

I would actually tend to agree for anything 500 hp and less. But, in situations where you are shooting for 600 to 700 hp, then a 351 is a very good option. If you are going Dart and shooting for that HP level you will be buying all new anyway because your 302 stuff isn't going to support those HP levels.
To me, that is where a 351 makes since.
But below that level, certainly not worth the hassle.

 

[a91what]

I work with guys all the time that take a junkyard 351, add cheap heads, a turbo kit..... I regularly max the 67mm turbos on the on3 kits at around 25psi... on a stock hyper piston bottom end in a 351. This will max a set of 60lb dekas easily before the turbo stops making steam so 80lbs are the go to on a budget.

FWIW these guys all end up in the 8.6-9.2s range in the 1/4 mile depending on skill level and vehicle setup. some have gone faster but that is not common and they have more CID and better parts.

I can get a 351w block for next to nothing, the rotating assemblies cost similarly between the two. mass is less a thing with good parts and no reason to not run IB on any build these days for the money involved. its RPM that kills the 2 main blocks due to the rotational mass the IB helps that immensely.

Heads will cost similar between the two of them, regardless i would never build a 357w as I can get more TQ for the SAME money with a larger CID.

FWIW I put my 351w in my fox for less than the cost of the dart block, I would have had to buy the heads, cam, intake anyway so there cost is negated. I did have to buy a UPR k member to make it easy, but all in all the only cost difference was the one AC bracket i had to buy.
Lets step back into the realm of reality, it makes no sense to stroke a 302 when you can do a stroked 351 for the same money.

 

[JD1964]

touche

 

[ras50gt]

I work with guys all the time that take a junkyard 351, add cheap heads, a turbo kit..... I regularly max the 67mm turbos on the on3 kits at around 25psi... on a stock hyper piston bottom end in a 351. This will max a set of 60lb dekas easily before the turbo stops making steam so 80lbs are the go to on a budget.

FWIW these guys all end up in the 8.6-9.2s range in the 1/4 mile depending on skill level and vehicle setup. some have gone faster but that is not common and they have more CID and better parts.

I can get a 351w block for next to nothing, the rotating assemblies cost similarly between the two. mass is less a thing with good parts and no reason to not run IB on any build these days for the money involved. its RPM that kills the 2 main blocks due to the rotational mass the IB helps that immensely.

Heads will cost similar between the two of them, regardless i would never build a 357w as I can get more TQ for the SAME money with a larger CID.

FWIW I put my 351w in my fox for less than the cost of the dart block, I would have had to buy the heads, cam, intake anyway so there cost is negated. I did have to buy a UPR k member to make it easy, but all in all the only cost difference was the one AC bracket i had to buy.
Lets step back into the realm of reality, it makes no sense to stroke a 302 when you can do a stroked 351 for the same money.

Now you got me leaning toward the 351w lol. I have it narrowed down to going 347 Dart or 393w Stock block. I have had my 93 GT since 2001, was my first car and plan to restore and keep it in the family. I do like the idea of doing it right the first time but also like the idea of saving some money not using the dart. I know I will be happy with 400-450 now but may eventually want more. I'm very unsure if the 351 swap will be more of a headache.

 

[Ragtop50]

Now you got me leaning toward the 351w lol. I have it narrowed down to going 347 Dart or 393w Stock block. I have had my 93 GT since 2001, was my first car and plan to restore and keep it in the family. I do like the idea of doing it right the first time but also like the idea of saving some money not using the dart. I know I will be happy with 400-450 now but may eventually want more. I'm very unsure if the 351 swap will be more of a headache.

If you are going to go to a 8.2 Dart stroker, I would go 363 vs 347, cost is same.
And really the same suggestion for a 9.5 stock block stroker, may as well go 408 vs 393.

 

[ras50gt]

If you are going to go to a 8.2 Dart stroker, I would go 363 vs 347, cost is same.
And really the same suggestion for a 9.5 stock block stroker, may as well go 408 vs 393.

So do you suggest the 408w stock block over the 363 dart for my goals?

 

[2000xp8]

Look, I've been doing this a long time. Have broken more crap and had more parts than I care to admit.
Admittedly none of those engines were 351 based. Not because they can't work or I couldn't afford it, but because I never found a reason.
To me it's simple.
If you are good with 400rwhp, no nitrous, no blower, just build a stock block 347, use the 11r's, a custom cam and an rpmII intake. Should net you around 400-425rwhp. How do I know? I ran a B block except extrude honed TW's, same parts, made 420rwhp. (sold in it's entirety , literally every single part including the harness and computer, to fund my terminator conversion). My combo was based on another that used same parts except canfield heads and made 5 more hp. Too bad those heads were know to crack between the valves.
To be clear, a b block is slightly different than a stock block, but for all intensive purposes, has about the same limits (I've literally witnessed high rpm eat one).
BTW, my 347 had hyper pistons, was made by ford racing and get this, cost me $2200 at downs ford in NJ (way back). Seems in 2020 you can barely get a 306 for that much.

You want more rpm? Run an r block, boss, A4 or dart block.
Along with more rpm, you get something that is pretty much limitless. You can do anything you like with it, any time you like. You want all motor at 7500rpm? Add solid lifters and cam and go ahead. You want 1200rwhp with turbo's? Go ahead. T trim or YSi, sure.

I've had my chance to own pretty much anything you can name, it comes in handy when your buddy owns (now owned) a mustang shop based on foxbody's.
My biggest regret? Turning down all those race blocks. I must have passed on different ones 10 times (guys that pay someone else to build their race cars, don't tend to be wisest investors).
Had I just accepted the last offer of a r302 in need of a rebuild for $1000, I probably would not have ever went the terminator route.

I'm not saying a 351 can't work, but nobody seems to prove it's worth the effort.
Notice that rarely do we get numbers from regular average owners with full weight street cars.
I could quote race car crap to i'm blue in the face, I just don't see the point, it's not relevant on stangnet.
Any car I ever mention is complete, from rear sets to AC.

Be nice to hear from 351 owners that put their cars on the dyno.
I have nothing against a 351, I just fail to see a substantial advantage or enough cost savings.

 

[revhead347]

Problem there is a dart block is going to make it a good bit more expensive than a 351. That's one main reason people go the 9.5 deck route, can be a good bit cheaper than a dart block and of course the ability to really go up in cubic inches. There are plenty of 351/357s running around putting down 650/700+ hp on a stock block, it can take it.
Also, a dart block will be heavier than a stock block 8.2 deck.
Dart block is great, but it will be more expensive.

But keep in mind, you may have issues installing your supercharger on a 351 without a proper or modified bracket.

That's the point of my argument. The swap parts and hassle out weight the initial buy in price of a Dart block. I am absolutely confident that there is 1%er out there that has put a 351W engine in a Mustang for less than the price of a 4 bolt main 302 block. I just don't think the average guy will be able to duplicate that build at that price.

Kurt

 

[Ragtop50]

That's the point of my argument. The swap parts and hassle out weight the initial buy in price of a Dart block. I am absolutely confident that there is 1%er out there that has put a 351W engine in a Mustang for less than the price of a 4 bolt main 302 block. I just don't think the average guy will be able to duplicate that build at that price.

Kurt

If he has a good intake and headers that will support a 347/363 already, then yes it could be more expensive going the 351 route. But if he has to buy new supporting parts anyway to do it right, then I can't see how starting out with a $2000+ block is going to come out cheaper.
More hassle with a 351? Depends...are you trying to squeeze it under a stock hood? Motor mounts are the same, transmission is the same. If you are buying new headers and intake anyway to properly support the 347/363 stroker, what is left? Distributor?
If you are just swapping "302" parts over to a 347/363 then you are cutting corners and is not a good comparison.

Every setup and situation is different, so no easy answer. You will get a lot of opinions, but I am not sure anyone can truly answer the question without a lot of details. There is a reason some people make good money being successful with doing such setups.

 

[2000xp8]

If you are just swapping "302" parts over to a 347/363 then you are cutting corners and is not a good comparison.

I wouldn't say this is true for sure.
My setup re-used all the parts except the intake, I had an RPM intake (kinda rare edelbrock version) and I went to an rpm II.
Same cam, same extrude honed twisted wedges, injectors, meter, equals, 75mm accufab.

Let's just say you could have a dart setup for $1000 more (i'll concede that it may could more, maybe i'm just used to getting stuff cheap).
If you are already going nuts and spending thousands, spending another grand probably isn't going to break the bank.

It very well maybe 6 to one half dozen to another.
Only difference being is that a dart (or any other race block), is an engine for life.
You will never encounter a situation where it's not suitable.

I could be bias, that's for sure. But i've really been craving a 7500rpm NA engine, so...

 

[ras50gt]

If he has a good intake and headers that will support a 347/363 already, then yes it could be more expensive going the 351 route. But if he has to buy new supporting parts anyway to do it right, then I can't see how starting out with a $2000+ block is going to come out cheaper.
More hassle with a 351? Depends...are you trying to squeeze it under a stock hood? Motor mounts are the same, transmission is the same. If you are buying new headers and intake anyway to properly support the 347/363 stroker, what is left? Distributor?
If you are just swapping "302" parts over to a 347/363 then you are cutting corners and is not a good comparison.

Every setup and situation is different, so no easy answer. You will get a lot of opinions, but I am not sure anyone can truly answer the question without a lot of details. There is a reason some people make good money being successful with doing such setups.

I'm starting with a almost stock 93 GT. It has bbk shorty headers and a magnaflow x-pipe with cats. I did notice those magnafloe xpipes are wayyy more expensive then back in 2002, but I would be pretty much starting from scratch regarding supporting mods.

 

[2000xp8]

I think we should back track a little bit and get some more details on the car, budget, time frame etc.
I know you had an 03 cobra, but we don't have much back story on your capabilities and fox knowledge.
A fox for the most part is much worse in pretty much every aspect other than being lighter than a 03 cobra.
The reality is that while you can just slap a 347 or 393 in, it will pretty much be a mess to drive.
Hanging with newer cars won't be a priority, staying in your own lane will be..
Chassis, brakes, suspension, transmission, coupled with an engine build, you are headed down what's likely a $20,000 project.
None of these parts are going to put up with 400rwhp+

Don't be insulted by my questions, I just no longer think like I did 25+ years ago when I bought the car.
I'm of the belief that brakes, suspension and chassis should be first priorities.
Not to mention we get a lot of dreamers through the forum that come in, want to make big power, take their car's apart and never to be seen again.

 

[ras50gt]

I think we should back track a little bit and get some more details on the car, budget, time frame etc.
I know you had an 03 cobra, but we don't have much back story on your capabilities and fox knowledge.
A fox for the most part is much worse in pretty much every aspect other than being lighter than a 03 cobra.
The reality is that while you can just slap a 347 or 393 in, it will pretty much be a mess to drive.
Hanging with newer cars won't be a priority, staying in your own lane will be..
Chassis, brakes, suspension, transmission, coupled with an engine build, you are headed down what's likely a $20,000 project.
None of these parts are going to put up with 400rwhp+

Don't be insulted by my questions, I just no longer think like I did 25+ years ago when I bought the car.
I'm of the belief that brakes, suspension and chassis should be first priorities.
Not to mention we get a lot of dreamers through the forum that come in, want to make big power, take their car's apart and never to be seen again.

I actually appreciate your post and your insight. The 1993 GT was my first car. I installed the headers and xpipe, replaced an alternator or two, starter, water pump, fuel pump, springs, radiator, various other repairs and a heater core. All of this was during high school and college. It was my daily driver until I got my 03 Cobra. I'd switch off driving them daily. The cobra was awesome and I have some regrets selling it, but there is just something about the foxbody that makes it fun. Of course it has sentimental value and blood/sweat/other bodily fluids lol. I also have some experience installing a 289 into a 67 coupe. Overall, I'd say I have decent mechanical abilities.

I agree with you in that suspension and chasis are important. The first thing I did with my 2013 gt was full suspension upgrades. That car still handled like poop. Was a big fan of the IRS in the cobra.

Back to the foxbody: I will have to freshen up a few items but brakes are on the top of my list. I plan to still drive it while restoring items but would like to build a motor on the side. Budget starting out is $2500-4k toward a short block. I also have a paxton sl1220 I was thinking of selling for heads or toward the dart block.

What do you mean by a mess to drive? I definitely don't want to get in over my head. I have no plans to track this car or get too crazy with it. It won't be a daily driver but want it streetable. I want to be able to take it on weekend cruises, be capable of a longer drive, have decent power. I think 450hp is nore than enough.

 

[2000xp8]

The reason I say it will be a mess is because with a 4 link, crappy control arms, shocks and springs, no subframe connectors it will be impossible to keep pointed straight.
Even in their best form, stock brakes and drums are only good for a couple stops.
If you run good tires you are sure to break a t5, if you don't run good tires you will be going nowhere fast.

Foxes are light and loose, 450hp magnifies that.

Me? I'd go for 94/95 spindles, wheels and tires and discs in the rear first.
If you want gears, do them at the same time the rear is apart (a gear change adds the most fun factor for the money)
I wouldn't put a dollar into 4 lug anything and I pray to never see a drum brake ever again.

Then i'd get real familiar with the maximum motorsports catalog, starting with subframe connectors.
If you want when you do the brakes and go five lug, do an IRS if that makes you happy.

Seems like you had the car for quite some time so you aren't going to get rid of it, go all high end parts, you won't have any regrets.

If your current engine doesn't burn any oil, I also see no reason why you have to go from 200rwhp to 450rwhp.
Consider working on the suspension and brakes and installing the Paxton.
Or if you like do a nice h/c/I setup.
300rwhp can be a blast in one of these cars with a good suspension (I like the road and track kit, except with front coil overs).
Trust me, an extra 100rwhp (one third more for perspective), is quite the bump in a 3200lb car.

The beauty of a fox back in the day was that you grew with it. A couple bucks here, a couple there and after a few years it all adds up to a really nice package.

 

[ras50gt]

The reason I say it will be a mess is because with a 4 link, crappy control arms, shocks and springs, no subframe connectors it will be impossible to keep pointed straight.
Even in their best form, stock brakes and drums are only good for a couple stops.
If you run good tires you are sure to break a t5, if you don't run good tires you will be going nowhere fast.

Foxes are light and loose, 450hp magnifies that.

Me? I'd go for 94/95 spindles, wheels and tires and discs in the rear first.
If you want gears, do them at the same time the rear is apart (a gear change adds the most fun factor for the money)
I wouldn't put a dollar into 4 lug anything and I pray to never see a drum brake ever again.

Then i'd get real familiar with the maximum motorsports catalog, starting with subframe connectors.
If you want when you do the brakes and go five lug, do an IRS if that makes you happy.

Seems like you had the car for quite some time so you aren't going to get rid of it, go all high end parts, you won't have any regrets.

If your current engine doesn't burn any oil, I also see no reason why you have to go from 200rwhp to 450rwhp.
Consider working on the suspension and brakes and installing the Paxton.
Or if you like do a nice h/c/I setup.
300rwhp can be a blast in one of these cars with a good suspension (I like the road and track kit, except with front coil overs).
Trust me, an extra 100rwhp (one third more for perspective), is quite the bump in a 3200lb car.

The beauty of a fox back in the day was that you grew with it. A couple bucks here, a couple there and after a few years it all adds up to a really nice package.

The current engine has been "tired" for a long time. Like any old ford it did burn a little oil but not too bad. Gas mileage was terrible, maybe too rich. I will also be checking compression. Figured id open it up to see how it looks. A few years ago I looked at quotes for rebuilds any where from $1600-1900. Figured Id be better off getting a complete shortblock at that point.

 

[2000xp8]

Engine work and shortblock pricing is kinda nuts these days. It's like anyone that needs an engine is between a rock and a hard place.
First things first, i'd fix the car if it's rich, that just doesn't happen, something has to be wrong.
My guess is that under normal driving you should see 15mpg-20mpg if you aren't in the throttle at every stop light.

I think no matter how you slice it, this project is going to get expensvie.
It looks like fordstrokers will do a 363 for $5000
Coast high performance $5150
And oddly enough CJ pony parts has a boss 363 for $4700 (seems like alot of value).
Cheap 351 shortblocks appear to cost about $1000-$1200 less.

I'd buy from one of those 3 or have it built locally.

 

[96pushrod]

The reason I say it will be a mess is because with a 4 link, crappy control arms, shocks and springs, no subframe connectors it will be impossible to keep pointed straight.
Even in their best form, stock brakes and drums are only good for a couple stops.
If you run good tires you are sure to break a t5, if you don't run good tires you will be going nowhere fast.

Foxes are light and loose, 450hp magnifies that.

Me? I'd go for 94/95 spindles, wheels and tires and discs in the rear first.
If you want gears, do them at the same time the rear is apart (a gear change adds the most fun factor for the money)
I wouldn't put a dollar into 4 lug anything and I pray to never see a drum brake ever again.

Then i'd get real familiar with the maximum motorsports catalog, starting with subframe connectors.
If you want when you do the brakes and go five lug, do an IRS if that makes you happy.

Seems like you had the car for quite some time so you aren't going to get rid of it, go all high end parts, you won't have any regrets.

If your current engine doesn't burn any oil, I also see no reason why you have to go from 200rwhp to 450rwhp.
Consider working on the suspension and brakes and installing the Paxton.
Or if you like do a nice h/c/I setup.
300rwhp can be a blast in one of these cars with a good suspension (I like the road and track kit, except with front coil overs).
Trust me, an extra 100rwhp (one third more for perspective), is quite the bump in a 3200lb car.

The beauty of a fox back in the day was that you grew with it. A couple bucks here, a couple there and after a few years it all adds up to a really nice package.

Pretty good info here. While the fox chassis isn’t great from the factory, getting it ready to accept a 400+whp build doesn’t really take a whole lot.
Sfcs, control arms, and torque box plates will get you a good bit of the way there. Then drop another $700 for some good suspension parts and you’ll have a pretty good start, and a car which will track straight - in a straight line at least.

Can’t argue with the comment about a t5 being the weak point. It’s best to think of an upgrade, unless you have multiple t5s stashed somewhere, even then it’s wise to upgrade. If an auto car, you’ll at least want to change the essentials.

When I did my dart block I wanted to start at a 347, spray it a bit, and then when I rebuild go with a 363 for some extra cubes and go f/I. If I did it all again I’d probably do it the same way.

 

[Ragtop50]

Very, very good advice above on getting your suspension in order. Back when I was younger, I had a 1967 Mustang that received a lot of attention under the hood, not so much on the suspension. The car sounded good, but did not handle very well.
I learned from that and on my 1990 vert, I have been giving the suspension as much attention as under the hood (if not more) and it makes all the difference. I have held back on many engine mods until I get the suspension and the rest of the drivetrain up to par.
Now that I am there, I can proceed and have a much more enjoyable car. It is not cheap, but if done right the results are worth it.
Did it slow me down? Absolutely, but patience is something you better have or bad decisions will be made.
I would rather have a bone stock engine in a fox that handles and rides well versus 4000whp with the stock suspension.

 

[7991LXnSHO]

I’m thinking about what Olds, Buick and Cadillac, (the more luxury minded branches of GM) did when they wanted A bodies and yachts to move and be reliable. They added cubic inches, lots and lots of them. If you want it street friendly, big cubic inches, good heads and a custom cam will be more reliable than a smaller motor with forced induction. A torque monster of around 400 cubic inches should be a blast in a Mustang, even without the parts to support full flow CFM at 6000 rpm. That you can do it with the weight of a 351 W instead of a 460 block is a bonus.