03-04 cobra eninges or coarse, because they come with forged goodies. Aside from that I would say the newer mach 5 speeds or 99+ cobras, because they have high flowing heads and a a forged crank. Next I would say 99+ gt's because the heads and intake out flow the 96-98. 96-98 would ahve to come last because, well basically the heads, intake, and cams suck.
dont know about 05's because I havent heard alot about them, but they make good stock power
