302 head work

[rattlerstang66]

I have a 302 with a 4spd man tranny. I am looking at the cheapest performance upgrades for my engine. I am wanting it to put out around 320+ hp without breaking the bank. I have been out of the loop on old school engine tricks now and could use some ideas. I have thought about finding some 351c heads and using them vice spending the thousands on two new performance heads. Any suggestions on what I could do with my existing 302 heads as well. For those who are not familiar with the HI islands it is dam expensive here to ship things so anyone on the islands out here have any good shops that wont charge me the Haole price would be appreciated too.

Sharky

 

[steel1212]

If you don't find a shop to do the work there I would suggest getting a good set of aftermarket aluminum heads so your not shipping more than once if don't get the performance you wanted the first time just to save a buck.

 

[danny clemens]

You could probably get some early 351 W heads fairly cheap. They are good
stock heads. A lot better than stock 302 heads. With a little porting and valve work they would be much better. If you want 320 hp you'd probably have to go with aftermarket heads. Some aluminum heads sell for not much more than $1,000.

 

[65ShelbyClone]

First of all, do a search of the Classic Tech forum. This is the question that most new members ask first and as a result it has many answers. You may also find other helpful information that wont come up in this thread.

320+hp(at the flywheel or back tires?) wont happen without essentially building the whole engine. Dont bother with 351C heads, save them for a Cleveland. You can get better results more easily with Windsor parts on a Windsor. You didnt say what things you already have on the engine(like intake, carb, exhaust, etc). I'll assume its all totally stock and with that an intake and carb would be a good start.

 

[Stang_1973]

Maybe you can find some GT40 heads somewhere and get them worked. I beleive you can get them off some late model 5.0's and Explorers. Dont be fooled by GT40P heads though. I here they are troublesome.

 

[Hissing Cobra]

As far as iron heads go, it used to be the norm to use the '69-'70 351W heads to produce the most power. These days, it's not cost effective to use them. Why? Because you'll have to have them ported, polished, hardened seats and larger valves installed and then machined for screw in studs. After paying for about 15 hours of labor, it wouldn't be too much more expensive to go with aluminum heads.

That's why I chose my AFR 185's for my 306 in my '79 Cobra (dynoed at 307 rwhp and 278 rwt.) My twin brother is an automotive machinist and does this work daily. When it came time to build my engine, he looked at all of the work it would take to modify a set of the 351W heads and advised me to buy the aluminum heads instead. I'm glad I did. However, he's got a set of those 351W heads on his 306 powered '85 GT and he dynoed at 311 rear wheel horsepower and 287 ft. lbs. of torque at the wheels. Not bad for a small engine. He runs 12.50's @ 109 with it too. They can be made to produce as much power as aluminum heads.

If you buy the Edelbrock heads, cam, intake and carb package, it'll get you to your 320 rear wheel horsepower goal. My uncle bought this package and that's what his '65 Fastback dynoed at.

Whichever direction you go in, good luck!

 

[Max Power]

However, he's got a set of those 351W heads on his 306 powered '85 GT and he dynoed at 311 rear wheel horsepower and 278 ft. lbs. of torque at the wheels. Not bad for a small engine. He runs 12.50's @ 109 with it too. They can be made to produce as much power as aluminum heads.

Maybe they can on a 306 compared to 185s, but they can't on a 408 with 225s. They definitely have their limits.

 

[Hissing Cobra]

Understood. However, he's talking about a 302 not a 408. That's like comparing a Boss 302 to a Boss 429.

 

[302 coupe]

320 hp can be made with stock heads, with just a mild port cleanup and some basic bowl work. Find a how-to article on the web, buy a few carbide bits for your die grinder, and you can have your heads doing pretty good for a weekend's worth of porting. Throw on a performer rpm or weiand stealth intake, 600 cfm carb, a cam with 225-230 [email protected] with around .510 lift, and some 1 5/8" longtubes, you'll get the power you want. Its pretty simple to get 320 hp from a 302, definately don't need a $1300 set of fancy aftermarket heads.

 

[Cobain03]

is this an old non-rebuilt engine? is so i wanna know what happens with heads. im afraid that more will go wrong when installing new heads.

 

[rattlerstang66]

Thanks for all of the advice given so far. It has given me a few more ideas. Here is some more info on the engine. It is a 69 302 2bolt main stock, first heavy rebuild will be this one, at least to my knowledge. What I am looking at using so far is an edelbrock air gap manifold with a holley 600 4bbl, not sure on the exact cam yet, that will go along with the heads. I also plan on using a 10.1 compression ratio piston. and tri y headers. There is lot of work to do on the stang and my budget I would like to keep is around 2500 if possible for the engine. Now if I take my stock heads does anyone have any tricks to flush out a few more ponies at the rear wheel.

 

[302 coupe]

after just switching from tri-y's to hooker comps.....don't even waste your time with the tri-y's. The hookers fit great and make more power. Don't do it twice.

 

[Tubo(2-bo)]

IF your planning on building up the 69 302, why not find a good used Exploder(Explorer) 5.0 . Youd have a lower end you wouldent have to rebuild w/roller lifters, and depending on what year engine you got, either GT-40 or GT-40P heads. A little home porting & your good to go.

 

[rattlerstang66]

Okay I found a place that can do the head work for a reasonable price, so I am going to stick with the stock heads, anyone have suggestions on what size valves to use when they get rebuilt? Once again thanks for all the advice, I will be updting the information on the car with pics as the project goes along. Also anyone else here from Hawaii?

 

[65ShelbyClone]

IF your planning on building up the 69 302, why not find a good used Exploder(Explorer) 5.0 . Youd have a lower end you wouldent have to rebuild w/roller lifters, and depending on what year engine you got, either GT-40 or GT-40P heads. A little home porting & your good to go.

All those are good considerations, but latemodel blocks are not entirely drop-in. Since he has a manual trans, he'll need the retrofit engine side z-bar pivot, probably a new 50oz damper with the early style shape, and a 50oz flywheel.

 

[rattlerstang66]

Okay, well new updates to the my baby include this, my 4 spd is gone I wil lbe using a c4 now. My plans now include the following, this includes advice from you all.
Heads: stock, machine both intake and exhaust ports, refit larger valves.
Intake/carb/cam kit: weiand stealth/ holley street avenger 670/lunati voodoo cam
exhaust: hooker comp headers, flowmaster american thunder series.

That is where I stand right now, more to come, if there are any suggestions out there on my latest direction, just let me know.

 

[65ShelbyClone]

You were planning on giving me that 4-speed, right? Why the switch to a C4? (Just curious; I'm die-hard for manual trans).

I wouldnt go too big on the valves unless you plan on really building that engine later on. I'm thinking around 1.84 intake and 1.54 exhaust like Ford Motorsport heads. Any larger and the ports wont be able to take advantage of the valve and it will be wasted.

 

[bnickel]

a popular swap for small block ford heads is to use 1.94/1.60 valves, but the 1.84/1.54 valves will work well also

 

[rattlerstang66]

Well long story short, this mustang literally fell into my hands, from some friends of mine. They were using it as a parts car, and were going to take it to the junk yard after pulling the parts they needed off. So I stepped in and saved her. The 4 spd is what she had in her befor on eof the guys got it and oulle dit for one of his old broncos. He got rid of the old bronoc and was goign to give it back to me when all of the sudden he had another one fall into his hands, so he is selling me his old engine and tranny out of his 68 stang he had resotred befor. So now I am going to be going back to auto. I do prefer manual myslef too, but you do what you got to do.

 

[splogan]

well where are the pedals going, a manual pedal setup is definitely worth selling to somebody going the other way.