gt40 heads
Elder User
Joined: Nov 2009
Posts: 666
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From: Chicago area
On a 302 and the right mods you can get a easy 350 hp. With porting and the right parts over 400 but that's about it. To see 450+ you need to go to the Ford Racing aluminum GT-40X or Z heads or go aftermarket.
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
You won't get anywhere near 400hp with regular GT40 heads, maybe a bit over 300hp at the crank but that's about it. To get up into 400hp territory you need to step way up to heads that flow as much as the AFR185's.
Junior User
Joined: Apr 2010
Posts: 56
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oh okay. what about these heads? FORD Assembled Aluminum Cylinder Heads 190cc SBF 351W : eBay Motors (item 330432118423 end time May-16-10 18:57:58 PDT) they seem legit and power making to me. correct me if im wrong though. this is the first performance motor i have built. we other than dirt bikes. 
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
Those Procomp heads are a definite step up from iron GT40's but they fall a little short of the offerings from TFS and AFR. If you want a real bargain on heads look at the RHS irons on summit racing, you can get them for about $500/ea fully assembled and these will flow well enough to get the HP numbers you want.
Junior User
Joined: Apr 2010
Posts: 56
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okay thanks for all of the advice and sorry about kinda hijacking the thread i figured it would be a little over repetative to start a whole new one just to ask the same ol questions i m sure everybody asks a t some point. what heads would be the best bang for the buck in the 600-1200 dollar range for a pair? i dont really have a cap on the horsepower i want just on what i am able to spend. thanks.
Postmaster
Joined: Mar 2005
Posts: 2,949
Likes: 6
From: Earth
You can't beat the FRPP X303 heads for value - $1,000 assembled and they're just a proverbial rch short of the AFRs when it comes performance.
Postmaster
Joined: Mar 2005
Posts: 2,949
Likes: 6
From: Earth
If you want a 400hp 302, then here's your blueprint:
Ford Racing Performance Parts - [Part Details]
Probably another 20-30hp to be had with a newer cam grind, maybe.
Ford Racing Performance Parts - [Part Details]
Probably another 20-30hp to be had with a newer cam grind, maybe.
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Junior User
Joined: Apr 2010
Posts: 56
Likes: 0
Im going for a 400hp 351w. how well would these heads work?Patriot Performance 1102 - Patriot Performance Freedom Series Small Block Ford Cylinder Heads - Overview - SummitRacing.com
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
They come with 1.84/1.54" valves, but don't waste your money installing larger valves in them because they are of no benefit without porting, and for what all that will cost you could have a much better heads.
Cargo Master
Joined: May 2007
Posts: 2,071
Likes: 36
From: British Columbia
"How well would these heads work?
Patriot Performance 1102 - Patriot Performance Freedom Series Small Block Ford Cylinder Heads"
Well I guess you better buy those. If you don't, then presumably you're not patriotic... and hate freedom.
I wonder where they're made.
Patriot Performance 1102 - Patriot Performance Freedom Series Small Block Ford Cylinder Heads"
Well I guess you better buy those. If you don't, then presumably you're not patriotic... and hate freedom.
I wonder where they're made.