I'm looking at doing something on my 302 for heads. I have a 1970 block with a xe262 cam with a 351w firing order. New lifters, timing set, springs retainer, locks and valve seals. Also picked up some 1.6 rockers and some pushrods as well. I have an offy 4bbl dual plane intake with a holley 570 that I plan on putting on top. The heads I have are very restrictive and need to be worked or replaced. I found a set of aluminum procomp heads 210cc intake runners and 60cc chambers. They come with new springs and full roller rockers. I can get these for about $700-750. They are almost new. Otherwise I found a set of Gt-40 heads for $400. Should I pay for the machine work on my current heads or buy one of these two sets of heads, or something all together different? Any ideas and opinions would be appreciated. Sent from my iPhone using TJJ app
Do the GT40 heads require roller rockers, and a roller cam too? The GT40s are probably better for a street car, better part-throttle response, but that info is just from reading Mustang sites, not any actual experience I have. I'm curious too - it seems like the procomp heads are a decent deal. Roller cams / rockers free up some HP
i had a set of cast iron gt40 heads on my falcon years ago. they performed well. i was running a larger cam than you have and a 650cfm carb.
I'm not sure if I would need a roller cam for the GT40 heads. I don't think so. I have a flat tappet cam in now. Sent from my iPhone using TJJ app
I have the GT40 heads on my 289 because they were $25.00 at the scrap yard. I love em. Used roller rockers and hyd cam (Edelbrock performer rpm) I haven't had a problem yet. Alot of guys on the mustang sites are stuck on trick flow or other aluminum heads but the GT40's are damned near what was used on the GT40 engines making the engine more HAMB friendly!
The heads do not require them, and those are likely the best option you have, unless you can find some early heads, and in the 302, that probably is not a great likelyhood. Remember though, if you got to the GT40 heads, you have to change out your exhaust manifolds, the spark plugs stick straight out, and the exhaust runners go up before they head to the collector, instead of down. (might be the GT40 P heads only, but have never seen an actual set up of just GT40 heads yet). You could spend some money on what you have, and have the machine shop put bigger valves in, not the cheapest, or easiest solution, but, if you would have to change out your exhaust, and you already spent a lot on coated headers, it may be a wash money wise....
$400.00 is a little steep for GT40 heads. If you're going to change the springs, rockers and valves, I'd pass on em and look for an Explorer in a junk yard and spend some money at the machine shop cleaning them up.
The GT40 heads use the same exhaust manifold, but you're right about the GT40Ps being different, spark plug orientation etc. The GT40s were used on early explorers and the "P" head was used on later ones. I have no idea what other fords had them. As far as clearence Clarence, you should be good. I have domed pistons on stock rods and crank, but then again I have a 289, so make sure you check with some putty before you crank it.
I guess if your going for fad, then specifics dont matter, but I like HP, so specifics matter..... many questions before you can choose which head. Runners and ports size is going to reflect RPM when making power... WHat kind of Pistons do you have?, what heads did you take off? Valve clearence ect.... Sometimes runner and chamber size can negativily effect power... SO does , if its an automatic, with a low lock converter.... My opinion is, get the info from the cam company, or download an engine build program, and punch in what you have, see what makes best power for your application.... Make sure you use copper head gaskets, and check valve clearence.... DOnt forget companies like Jegs or Summit, you can use there tech dept, and they sell procomp, and gt 40 heads
Edelbrock Performer RPM heads are a significant upgrade over stock GT40 heads, but they are still suitable for a real world street car. And, they are lighter.
The heads are stock 1970 302 heads, pistons are stockers as well. Only changes I have made are the cam and timing set so far. Sent from my iPhone using TJJ app
Make sure you have enough compression for the cam being used. If not you will be giving up some of your gains.
Do some googling on those pro comp heads. I think that'll make your decision easier for you. I have not read many forums were people were happy with the pro comp heads.
ProComp stuff is pretty much cheap junk across the board- epay is flooded with that crap, looking to sell to folks who like the price. Rockers and such are real bad- you get what you pay for. Run, forrest, run...
GT 40 heads were also on some of the Mustangs, as I am being told. I know that M word makes people cringe, as it sometimes does me(and I am a Ford guy)... With that said, it is about sourcing the parts, not fixing the stang... GT 40 P heads and GT 40, if you can find a set, are able to be had at most bone yards that have stuff moving through them. I bought a set for 60...after I convinced the idiot behind the counter that they were indeed steel heads, not aluminum....(in his defense, he was not issued a magnet, and was likely held accountable for stuff leaving cheap)...I would have thought that the rust was a dead giveaway....
The GT40 heads are GREAT with good flow and will handle 500 hp if you do some porting work . I would get the heads redone and have the head shaved to make sure it's straight . You DON'T have to use a roller cam either ! I have no idea where that person came up with that one but you can use with a roller or flattap cam . If you keep your heads you will have better compression but I would also have the heads redone and have bigger valves installed . On the other hand if you are going to spend that much on 302 heads , I would start searching the bone yards for a Mustang Cobra and get a set of GT40 heads that way . Now if you are using the car mostly for street use then I wouldn't port the heads too much . That way they will be smaller and give you that low end torque needed for the street . Now if you are going to race it every weekend then open the heads up for better flow . Just remember to make sure you are getting GT40 heads and not GT40P heads ! Also stay away from ProComp ! If you buy them you will need to do alot of work before they are really good to use so save your money ! Retro Jim
If he thought the heads were steel he really was an idiot. Regardless of what TV sports announcers keep telling us, heads and blocks(even race heads and blocks) are iron, not steel.
GT-40P heads never came in Mustangs. They only came in 5.0L V8 Explorers and Mercury Mountaineers. The P heads are a decent head. GT-40 heads only came in the COBRA Mustangs in '93-'95. If you want good street heads, check out thumperoforangepark.com for some ported 5.0 E7TE Mustang heads (came on all the regular '87-'95 5.0's) that have very good flow with small valves. Port velocity and throttle response baby!!
Thanks for all the info, I will look into all of the options and pass on the procomp heads. Sent from my iPhone using TJJ app
I've never seen a good report on the ProComps. I am running Edelbrock Performer RPMS on the 331 in my 27 and LOVE them. A little more money but they are so good right out of the box that they are worth it. Don
If you want to run steel, World Products Windsor Jr. steel heads are hard to beat. Ran them on our stangs with very good results.
I can't make any comparisons between heads because when I built my 302 I started with GT-40 heads but I can say that the changing from the stock rocker arms to Howard Roller Rockers made a huge change in my motor. The power difference was noticeable and it cut out a lot of noise from the clattering the stock rockers made.
Honestly, I would really consider the heads Moneymaker is showing.... They are all set up... They make alotta HP too... It looks like they or 2:02s already.... I personaly run edlebrock Vic Jr 2:05s.... but thats affordable HP in my book...
I have a good set of d00e-c 351w heads ( best SBF production heads according to my machinest and mustang buddies) and I wouldn't spend any money on them I'd buy the heads Moneymaker has if they are better than Pro Comp, or Edlebrock heads. I'm trying to talk my buddy out of buying them right now as it would cost a minimum of $225 just to get them machined for the pedistal roller rockers off the e7te he has on the motor now.
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