HI
I got a 69 mustang 302 stock. im trying to get a some more horse power aand i got a gt40 heads i got from the junkyard. what can you guys recomend me to. also i got a freind that can get me edelbrock stuff with a discount. what cam and intake can i use t=with the gt 40s
to get the best gain out of it i would really apreciate all your input thank you.


ps tha engine is new anly about 500 miles on it.

thank you

 

Best place to post this would be the 5.0L section.

 

sorry i can't answer your question but how much did you pick the heads up for?

 

No need for the 5.0 section.

Are they GT40's, or GT40P's? P heads require special headers to clear the spark plugs.

Assuming they're not P heads, I'd recommend an Edelbrock RPM Air Gap, Comp Cams camshaft (not a huge fan of the limited Edelbrock grinds), and a 500-600CFM carb depending on cam selection.

If you can tell us more about your car and driving style, we can recommend a cam for you. Auto or manual? What rear gears do you have/want to run? Do you drive it every day, or only occasionally for fun? Do you do any freeway driving? If so, how much?

 

GT40 heads are generally consider stockers or Janers and do not flow much as they come. They can be worked to get flow, but are basically stock heads otherwise. There is nothing wrong with them, but you are not going to get a bunch of power out of a plane set of GT40 heads. I have a set on my 351W in the '88 Bronco and they are a limiting factor in getting performance. If I every want to shoot for more power, I would need to port and polish the heads and possibly machine for larger valves or just replace them with something was was already ready to go.

As for intakes, I like my Air Gap on the 383W, but it is tall so will not fit underhood in all applications.

Cams...I like my Comp solid roller cam.

Like Star said, if you let us know your targets, we can help a little more

 

Urban, for 289/302 heads, GT40's are pretty decent:P The reason they're good for the smaller engines is because they basically use 351W port castings without having massive chambers. That's also the reason they're the limiting factor in your Bronco; they're simply not much better than stock 351W heads.

 

Good point. Did not think about the fact that this is for a 302. I am so used to thinking 350-400cid these days.

 

bah @ you and your monster motor... :P

 

From what I read today, the GT40 heads have 145cc intake runners with 1.84/1.54 valves with a peak in the 187/129cfm range at .5 lift. Seams like performance 302 heads often in the 165cc range with 1.9/1.6 valves with 243/185 flow at .5 lift. Stock 302 heads are 127cc runners with 1.78/1.45 valves with 150/113 flow at .5 lift.

It looks like they are still far from performance heads and could use some tuning to get them going but are better than stockers. Basically stock 351 heads on a 302. Am I wrong?

 

you will notice a big different with the gt40 heads


very good bang for the buck