Best heads for 302

[RadRacer203]

Just joined the forum today, I've got a '71 Mustang with the original 302 and an AOD trans in it. It's already got and Edelbrock Performer intake and Holley 750 on top, I was thinking of putting on some new heads (and headers/exhaust) for more flow and better power. Just wondering what I should look into. I'm looking for something I can find fairly cheap, like other stock heads, but I'm not sure what to look for. I'd like to keep the stock cam because it's so smooth, I just want a little more power out of the engine with some better flow. I heard that 351W heads are a good option, but I want to get some other opinions.

 

[delawarebill]

http://diyford.com/choose-heads-small-block-ford-rebuild/#

see if that info helps u.. and that 750 carb is way too big for a 302.

 

[RadRacer203]

http://diyford.com/choose-heads-small-block-ford-rebuild/#

see if that info helps u.. and that 750 carb is way too big for a 302.

Thanks, that's definitely a step in the right direction. It looks like there are a bunch of gt40 and gt40p heads on craigslist right now. Not too many other options apart from a set of Victor JR's. Should I go for one of these or hold out for something else? 

BTW, I decided on the 750 to pull less vacuum for a firmer brake pedal. Runs way better than with the 450 it had when I got it. Might be a little big, but I like it.

 

[RadRacer203]

There are also a couple sets of E7TE heads for really cheap, complete with rockers. Are these any good? They're not on that website

 

[73pony]

Welcome to the forum from Iowa. I will reiterate that the 750 carb is too big. Especially with a stock cam. While swapping heads and adding headers will create a bump in power you might want to rethink your decision on the cam. Heads and headers that flow more are still limited by the cam, no change in the duration or lift will still result in pretty much the same flow rates as with your stock heads.

 

[Jeff73Mach1]

Stock 302 heads from the early 70's aren't bad. I think 351W heads are not worth the trouble. If you feel the need to change them, try and go aluminum and look for smaller chambers to increase your compression and save some weight.

If you are not increasing compression, then any power gains are going to be minimal.

 

[RadRacer203]

Welcome to the forum from Iowa. I will reiterate that the 750 carb is too big. Especially with a stock cam. While swapping heads and adding headers will create a bump in power you might want to rethink your decision on the cam. Heads and headers that flow more are still limited by the cam, no change in the duration or lift will still result in pretty much the same flow rates as with your stock heads.

Ok, I'll definitely think about a cam to go along with it. It's my daily transportation though. So I don't want to do too much at once because I still have to drive it

 

[Carolina_Mountain_Mustangs]

You are probably going street. When we use to build really hot 289 engines very high compression was the key. We had 14 to 1 and the guys would go over 10,000 rpm with them. Did not use head gaskets at all. If you are going to run higher rpms be sure you have screw in studs. If you go with double springs and high lift cam, Screw in studs.

With high performance come high failure. Racing parts do not make an engine last longer usually very short life, lol. One of the first things you should buy is RPM limiter. Broke valves from over rev. will kill you before you can react. You can get MSD and others with it built in. That is the weak point in most engines is valve float, broke valve then split piston and blown to bits.

BTW welcome to the forum from North Carolina.

 

[Don C]

This should help, it looks like the E7 has more potential, when ported, than the GT40, but the stock GT40 is better than the stock E7.

http://www.corral.net/tech/powerplant/head_tech.html

+1 on 750 being too big, and +1 on a cam upgrade. You can get a cam that will boost performance but still be good for a daily driver.

 

[delawarebill]

http://www.alliedmotorparts.com

ck this company out too.. i got a pair of heads from them this yr. they were really nice and i asked for '71 heads and he looked for them. said he had a pair on the shelf ready to go. and i got them in 3 days. the shipping box converted to a return shipping at NO extra cost to me...

 

[RadRacer203]

This should help, it looks like the E7 has more potential, when ported, than the GT40, but the stock GT40 is better than the stock E7.

http://www.corral.net/tech/powerplant/head_tech.html

+1 on 750 being too big, and +1 on a cam upgrade. You can get a cam that will boost performance  but still be good for a daily driver.

Ok, I think I'll probably go with a set of e7 heads and try my hand at porting. Definitely going to look into a cam, but not quite sure what to look for, any recommendations? I want something similar to stock- nice and smooth.

 I'm going to keep the 750 on. Everyone says it's too big, but the engine runs perfect with it. Not going to change what works

 

[Jeff73Mach1]

An oversized carb that is properly tuned and set up, works fine most of the time. You may be giving up some throttle crispness but I wouldn't worry about that too much. An engine draws air and the negative pressure draws fuel through the carb. It only squirts on acceleration to cover up the fact that the engine needs a bit of fuel before the increased air flow can draw fuel in.

If your engine needs 600 cfm, a 750 isn't going to hurt it, but it will still only draw 600 cfm through it.

You can tune a carb by adjusting for maximum vacuum

you can tune timing by adjusting for maximum vacuum

your goal of reducing vacuum to make your brake pedal feel firmer is counterproductive to peak engine performance and efficiency

But it is your car and you like what you like so enjoy it!

 

[Don C]

You'll probably want something in the 270 to 280 degree duration range. The spreadsheet program here will give you something to play around with to get an idea of a starting point.

https://www.7173mustangs.com/thread-camshaft-selection

 

[RadRacer203]

Still trying to find the cam I want, but I'm picking up a nice set of E7 heads with about 20k miles on them for $50 this weekend. I think I'll try my hand at porting them over the winter and I'll clean them up and put in some new valve springs and rockers. If I don't screw them up too bad, I'll slap them and the cam on all at once when I get some free time.

 

[mustang7173]

RadRacer203,

How many miles are logged on the engine? It is known that an engine with a lot of miles, install a set of new heads, can potentially blow out your worn cylinder rings. I agree with the others, the Holley 750 way too big.

Plug in your information to see what the max cfm would be.

https://www.summitracing.com/expertadviceandnews/calcsandtools/cfm-calculator

mustang7173

 

[RadRacer203]

My engine has about 118k miles on it, but it's in good shape. Every cylinder has around 150 psi compression.

 

[mustang7173]

RadRacer203,

Ok. as long as you do not put lot more compression on them, you should be okay! I have the Tri-State Flow-Tek heads.

https://www.flotekheads.com/product-category/small-block-ford/

mustang7173

 

[MeanMachine]

Out of curiosity, what about an E7 head is better than the original 1971 302 heads? I kept my D0OE heads from my '71 302 and worked them. I didn't see any reason to go to an E7 considering they had larger chambers than mine and a different style rockerarm mount design.

 

[Hemikiller]

...and the best heads in the world will do you no good if you don't have a solid bottom end. If it's got a bunch of miles or any blow by at all, don't swap heads until you freshen up the rest of the engine. A set of headers and dual will probably net you more seat of the pants HP than a set of heads anyway, especially with a stock cam.