Best Cylinder Heads?
 

I am looking for a set of heads for my mildly built 94 GT. I know that the aluminum heads make more power but is that just because of the weight savings and heat transfer or something else. I have a Cobra intake along with the usuals (TB, cold air, headers, full exhaust, 3:73's) and was wondering if a set of cast iron heads could get me 50-60 hp. Cost is a concern but not nearly as much as reliability since I drive my car alot. Do the aluminum heads blow more gaskets than cast? Thanx for helping.

There is a bunch of reasons that alum heads usually make more power.

Here are some:
- Aluminum transfers more heat allowing you to run higher compression with out detonating.
- Most aftermarket heads have larger valves
- Most aftermarket heads have larger runners
- Pretty substaintial weight savings. I don't know if you can feel it or not, but alum heads sure are lighter!

I've never heard of aluminum blowing more gaskets. I think maybe aftermarket cast iron heads with port work could get you 50-60 hp but may need port work. ?? I've heard stock ported heads can get you anywhere from 35-55 hp depending on which heads and how good the flow numbers are.

I think how much hp you gain from heads or head work also depends a lot on the over-all combination... cam, intake, exhaust, etc.

You will likely notice the car running hotter also with alum heads. I suspect it is the heat transfer thing. I don't thing there are many guys with alum heads that will tell you their card doesn't run hotter... This may also force you to upgrade your cooling system, like alum radiator, elec. fan, high flow water pump...

Hope that helps.
Disclaimer: I'm no expert, this is just what I know from reading and my limited experience with aluminum heads on my car.

Later, Dave

My car didn't run any hotter after I did my TFS TW heads. I use an autometer gauge, so I would see if it got hotter. Iron heads could technically make more power due to the heat in the combustion chamber burning the a/f mixture better I think. But, you wont see any after market iron heads that flow like an aluminum head like a TFS or AFR box stock for box stock. My 2 favorites for street 5.0 alum heads are TFS and AFR 165. With the alum heads u can usually run more timing which if the car likes more timing can make more power. Not all combo's like more timing though. You also get a nice 40-50lb front end weight reduction which is great especially for your heavy SN95. To get the power u want from a iron head would require porting and would substantially increase cost. IMO, stick with a nice alum head. Either AFR 165 or TFS TW. Also look into some porting on your cobra lower intake to better match the heads. Port it to a 1250 gasket which both heads I mentioned come out of the factory matched to.

Sweet GT btw!!

Mike

The best heads on the market for street/strip is DART. These heads have been proven time and time again. And about the debate whether or not Aluminum Vs. Iron which makes more power?? Well I've been and built plenty of competition racing engines and believe it or not, Iron makes more power simply because aluminum expands and anytime it expands it loses hp. So if your really into saving weight, then go aluminum, but if you want hp go Iron. Plus with iron you don't have to worry about warping your heads if the motor overheats....I've had that happen plenty of times!!! Hope this helps.

Eric

you said that your car was a daily driver so i would go with a set that were mild like the edelbrock performer or trick flow, i would stay away from all out race heads if you are going to drive it everyday, i have a 95gt 5sp that i drive everyday, i have edelbrock performer intake and heads(w/some port work)and i really like the way that they perform, my car didnt run any hotter when i installed the heads either.

i did some porting work myself, and i have the 1.90 intake valve,i havent had any problems with these heads, they have been through 3 of my mustangs over the past 3yrs. i didnt experiance any driveability probs.

i have to side with radicalGT (eric) on this one. for a daily driven mustang i think iron heads are the way to go. i mean, why do you think that they call aluminum heads a 50,000 mile head? because of warpage and expansion rates....

for reliability as well as power i would say get a set of nice iron heads and you will see good gains.

hope it helps,
adam

GT40P. Get new headers, and the heads fully assembled for less than $700. Home port them.

You could do well with a set of GT40 Irons that have been milled and ported as well. Pretty cheap, no header change necessary.

The Dart Windsor Jr's are good too, although I'm pretty unimpressed with their flow curve. You have no reason to spend an additional $300-$500 on aluminum heads, unless you really want to drop the weight. Without a cam the TFS or AFR heads aren't going to do anything more than the irons suggested. Even with a aluminum head and cam, you're only gonna pick up another 30hp over what irons will give you right now. You simply don't need 250cfm flow.