This is my 1st post over here i normaly post on ls1tech,but theres not alot of lm7 info over there...

anyway, I recently purchased an 03 lm7 longblock to replace my 98 ls1 that was trahed by high rpm oil starvation...Reason for getting this engine it only had 30,000 miles and was 450 bucks with harness pcm and everything....after selling the harness and pcm i have 250 bucks in a low mile shortblock...

car...98 trans am 4l60e with a 9" 4000 stall,373s, and alot of weight reduction...

engine and mods...
03 lm7
04 ls6 cam with yellow springs
fully ported 706 casting heads with sttock valves
cometic .030 gaskets"should bump cr a little"
arp head bolts..

bolt ons
equal length long tube headers
true duals dumped spiral flows
ls6 intake
ported tb
slp air lid

ive been looking and it seems some of you guys are making anywhere from 330-350 rwhp in trucks with baby cams...

my last 2 setups made 380rwhp with a baby cam and a little over 400 with h/c...

the car also has 2 stages of nitrous...will be a max shot of 175...
sorry for the long 1st post id just like a little input on this setup....

 

I'd say in the 320hp range since you have minor headwork. That ls6 cam is hurting you if you're wanting to make big power. Throw a real cam in it.

 

ehh ive had the big cams...alot of power is in head work....i left the small valve in the head because i dont feel a 3.77 bore needs any more valve...the heads will still flow in the 280-290cfn range...

i found this link awhile back...https://ls1tech.com/forums/conversio...onversion.html

i forgot to mention this was all done on a tight budget...if it only makes 320 so be it.... it will never be ran n/a at the track anyway...

im hoping for atleast 340 thats what my 156,000 mile ls1 with headers and an intake made...

 

But doesnt a stock LS1 put down about 30-40 horses more than a 5.3?

 

pretty much.....an ls1 with this setup wold make close to if not more than 400....