The 4.6 is a different animal. First off the 2v GT motors barely make 250 - 270 RWHP using every single bolt on, long tube headers and off road exhaust. With head porting and cams they barely eclipse 290 - 330 RWHP. For them to go beyond 330 RWHP NA takes a lot of money (machine work) and some light weight trick parts and even then its unlikely they will see 400 RWHP. In order for him to see 400hp NA he would need to drop in a 4v.


Hurst[/quote]


Ive seen an article with just a carb change and timing locked at 19 degrees
it layed down 290 hp then with headers it was 320 then mild ported heads no cams 380 ....

ive seen a ls1 motor pick up over 80 hp with just a carb change