suggested power?

Hey guys very soon i will be in the process of building a nice daily driver fox body. my plans were swapping it for a rebuilt 308 stock bottom end. I'm still in the process of looking for heads to use but I definitely can't go with alum. heads. to pricey. Yes there are great prices out there, but I want some iron heads that perform good. Ive considered thumper E7s or some GT40P heads. I found these GTs on tri-state cylinder heads website. Tri-State Cylinder Head - Chevy, Ford, Small Block, Performance, Aluminum Cylinder Heads for the pair that seems like a great price.

heres my question, with a 308, GT40P heads, comp cams Xtreme energy cam 284/296 duration and 544/541 lift, SVO 1.6 roller rockers, weiand dual plane intake, and 750 carb what kind of power do you guys think i'll have?

Ryan

I'm running the same cam and some bigger heads that I have maybe 290rwhp out of a 347. So powerwise out a 302, maybe 300hp(225rwhp) is my guess.

i just think i wont be happy with 225hp. actually, i know i wont be. got my eye on a windsor swapped fox body. i could work with that.

Originally Posted by 73FordDriver

i just think i wont be happy with 225hp. actually, i know i wont be. got my eye on a windsor swapped fox body. i could work with that.

Trust me you would make more than 225rwhp.

I run a 308, Gt40 irons with the bowls cleaned up, Air Gap intake, 670 Holley, 9:7 compression, 224@.050 (270 duration) and .532 lift on 110SLA cam.

I made 222rwhp and 250rwtq with no tune, crappy distributor, 600 edelbrock (at the time), and 8 degrees initial timing.

I hope to be at 240-250 with a good tune at least by now.

With the size cam you have picked out, which seems way huge for those heads, you should get more power and not have very good streetability.

That is alot of cam for a 302. When you use a cam that big with GT40 heads that is way past their potential. I am NO EXPERT but I know that you could do better.


If I built my 302 over again on a similarly tight budget I would have put ARP rod bolts, different pistons to make 10:5:1 compression, and a more modern cam like a Lunati Voodoo 268. I probably could have seen another 40hp or more. That would be about 350+ at the crank. Anyways I figured I would chime in since I have been there and done that...

I'd get the thumper E7s over those GT40s because the thumpers are ported. I'm not going to comment on the RWHP right now since it would be a guess.

I don't agree with the statement that that cam is too big for those heads. I agree if the cam were huge, but in this case what is the best way to help to compensate for poor flowing heads...a healthy cam.

Isnt that XE cam with 240 246@.050 duration going to make its power closer to 6500+ rpms? It just seems like heads that don't flow that well over .500 lift would not benefit from a big cam but I am FAR from an engine builder of expert. I only know what I have been told by my builder and some family members that have built 302's-351c's.

I really like the RHS Iron 180cc head for $950. I bought my GT40's for $300 including roller rockers and spent another 400+ on machine work including all new valves and components. Looking back I would have rather run the RHS heads but then again on a budget another 200-300 bucks is alot. (I was in college and working part time.)

It really is true what everyone says. Spend more money on the heads and less on fancy forged rotating assembly if you are going to run N/A.

My little Cobra replica has ran 12.5's with just 250rwhp. Race weight is about 2500#.

Lee