View Full Version : need help with a 408

12-18-2010, 09:55 PM
hi all ..i was told if i needed some good advice this is the place to go..

i have just purchased a used engine from a friend for my auto 2004 gto and it seems to be lacking in power and i was wondering what do i have to upgrade

i haven't dynod it yet but i raced an auto LS3 C6 with I/H/E/cam 470rwhp and i almost beat him with my street tires while he had drag radials but even though, i feel that it should be putting out more power.. am guessing am at around 490-500rwhp

the engine is a L98 stroked to 408
L92 heads
K&n intake
92 Fast Tb
102 Fast Intake manifold
a small cam (no details atm)
1 3/4 headers
a custom 2.5" exhaust

i was thinking of going the the 2005 - 2006 vararam or the AEM bute force
102 TB worth it?? what about headers? 1 7/8? worth it?

any help is appriciated

12-21-2010, 02:21 PM
You are making good power if you hung with that modded C6. Yes you could gain a little with a better intake and bigger headers though....

12-28-2010, 12:57 PM
I would try and figure out what the cam spec is. If the spec is not right for those heads there might be some power to picked up from there. 1 7/8 headers would pick you up some good power on a motor that size, as well as 3" exhaust if possible.