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You can use the factory heads, but it still won't make much more than 300hp even with porting and bigger valves. You can buy a better flowing set(GT40) for less than what the new valves will cost, and for a bit more you can get a lot better head.
You can use the factory heads, but it still won't make much more than 300hp even with porting and bigger valves. You can buy a better flowing set(GT40) for less than what the new valves will cost, and for a bit more you can get a lot better head.
Where do you get 300hp max from stock heads?
I was just wondering cause I ported a set of 302 heads that had 358hp potental and that was with 351W valves and a so so port job.
Last edited by HemiEater; Jun 18, 2007 at 04:51 AM.
As I have said, all the dyno sheets I have seen show about 300 crank HP give or take with ported E7 and bigger valves, Tmoss Porting has a nice article on some heads that flowed 228/182cfm and made 272 RWHP with a custom cam and ported intake through a T5. If you take 10% powertrain loss that's puts crank HP in the 300 range. I wouldn't expect the heads to make any more power on a 351, the bigger motor will reach the flow limits at a lower rpm that's all.