Engine Advice

[Muddy]

Going to be putting together a 302 for my Mustang. Trying keep it reasonable. Plan is to use my stock bottom end with GT40 heads. I have a performer intake to top it off and thinking about going with a Holley. Would like a good reliable engine with the most bang for my buck. This will be my first build of this kind. Looking for some advice on a few things:

1. Got a pair of GT40 heads from pick n pull. Going to have a machine shop go through them, but what should I have done? Any reputable shops, preferably in the south bay? Heard the spring from Explorers are weak.

2. What cam should I be looking for? Most power with good drivability.

3. Rockers? What ratio? Brand etc..

4. Any other parts or advice you have had good experience with?

[Fungus232]

Re: Engine Advice

Be careful with those GT40 heads. They're great heads as a bolt on upgrade but can't handle too much lift on a new cam. By the time you have a machine shop resurface them and machine them for studs (they're setup for pedestal mount rockers now) you are WELL on your way to a set of aftermarket alum heads that will flow much better.

I finished building a 5.0 a couple years ago that has been sitting on the stand and waiting to go into my '65 Comet back in Norcal. It is a 90 5.0L bottom end that I freshened up and rebuilt GT40 heads from a '96 explorer. When I had the heads done I had the stock E7 valve springs taken off and put on the GT40 heads as I'm running the stock Mustang cam. Also running some Ford Racing 1.6 ratio pedestal mount roller rockers. I've got the GT40 intakes off the explorer as well so it should be a real nice little engine for the Comet which is a pretty lightweight car to begin with (think trimmed out Falcon).

[Muddy]

Re: Engine Advice

So as long as get pedestal mount rockers they bolt on without machining? Can valves be reused? Was thinking about a good cleanup, no porting or anything like that. How much am I looking at?

[Fungus232]

Re: Engine Advice

Pedestal mounts are bolt on. Just make sure the cam you go with doesn't have more lift than the ped mount rockers allow.

To have my heads out here tanked, resurfaced, 3 angle valve job with the stock GT40 valves and valve springs R&R'd and shimmed to spec for stock mustang cam ran me $400. It IS Hawaii and you may be able to do better in Norcal but not by much I'd imagine. They looked brand spanking new when my guy was done with them.

[ThrillHouse]

Re: Engine Advice

I got this kit and freaking love it. not sure about with gt40 heads cause mine are stock, and my kit came spec'd higher than I ordered

http://www.summitracing.com/parts/hr...view/make/ford

[bent70]

Re: Engine Advice

If you spending $400 plus for the heads to be redone...toss them, they suck anyways especially those ones. pick up some afr165 and call it a day.

[Muddy]

Re: Engine Advice

I can't find any aluminum heads for under a grand? Just procomps and I've heard bad things. From what I've read I thought gt40 setups were decent low buck setups?

[bent70]

Re: Engine Advice

They are OK...better than a stock head. You have the iron gt40p heads from the explorer right. I have some svo gt40 y heads on my mustang and they are decent...although the previous owner ported them so I don't know how they are stock. The svo heads are better than the irons from what I have read.
My top end is efi, but on the heads I have 1.72 scorpion rockers cromolly pushrods and unknown springs. The cam is either a comp cam blower cam or a custom one...don't remember, but when I running without a supercharger it ran pretty strong still and was more than enough power for a mild runner....then with the supercharger....you can't get the grin of your face.
Basicly, you heads are decent, not as good as entry level afr165's, but should get you with a good can 280-300ish hp is setup really well. If you trying to stay real budget...toss in a stock 351w...you will have more power than the 302 and will feel stronger....well mine did

[Muddy]

Re: Engine Advice

Thanks for the input. Just figured since I had the bottom end this could be a reasonable/decent build. Any advice on a cam if I stay on the gt40 path?

[pippinmader]

Re: Engine Advice

It all depends on what you want to spend and how much power you want. Using the gt40 heads you have I would say you are going to be in the $750-$1000 range with stock rockers and push rods and be in the 250-275 hp range, is that what you are shooting for? ($500 for rebuild/parts for heads, $100 for gasket kit, $200 for cam/timing set)

I agree aluminum heads are nice, I am running them on my build, but you can build a good engine with those GT40 heads and a stock valve train (you might have to upgrade your valve springs to match the lift your cam has). I am a big fan of porting, the exhaust runners on Ford heads are known to be terrible, even if you have never done it you can really make a big difference, four hours worth of work will get you 20 hp or so on average, for free! I am not talking about complicated porting, just gasket matching and cleaning up the bowel area. There are lots of articles around that talk about how to port/gasket match

Again roller rockers like the Ford racing pedestal ones are nice, but the stock ones are fine for most applications. I say unless you are going to build a race engine keep your cam choice relatively mild, don't choose a cam with an RPM power band over 6000 or so, sure you will give up a little peak HP, but your overall drivability will be better, and it will "feel" like more power because the power will be in the range that you actually use. Is your block a roller block, what compression ratio do you expect to have? If you have a regular cam make sure to use break-in oil, regular motor oil will NOT work. I like to use double roller timing chains.

[plug ugly]

Re: Engine Advice

Im real happy with the comp 35-308-8 cam.

[ThrillHouse]

Re: Engine Advice

I posted a link in this thread for a howards cams off road cam and lifter kit, it's supposed boost low end torque and fuel mileage. I've noticed a huge gain in power with it

[Fungus232]

Re: Engine Advice

Im real happy with the comp 35-308-8 cam.

That's what I stabbed in the roller 5.8 that I need to get off my ass and finish and into the Bronco! That cam has too much lift though for ped mount rockers. He'd have to machine the heads for studs which drives the price even closer to aluminum heads.

[Muddy]

Re: Engine Advice

If I can get 250-275 reliable HP, that would be fine. Want to get something together to keep me motivated. A running and driving project will keep me going a lot better than one that just sits in the garage. That being said I don't want throw my cash away either. I will tearing down the motor this weekend to inspect everything, then I'll make some decisions. It is not a roller block and from some other opinions I've read, they say don't waste my time. Thoughts? Thanks for all the great advice!