anyone here ever dyno a LT4 kit on the LT1? It says 420+hp this is the intake, cam, heads, roller rockers........goes for like $2300. I wonder how much this kit produces on the LT1 for real......not what the ad says. SO what does it make?

Also how much hp can the LT4 heads handle? would the LT4 head be capable of making 600hp?

 

That is deffiantly not RWHP. I would say don't expect more than 350 at the wheels with all the bolton's.

 

Really? there are guys here running 330rwhp with stock heads and the Hot cam and rockers.

Yea the 420 figure is definately at the motor.

 

also on the question on the LT4 head capable of making 600hp that is independent of the kit........talking on like a stoker motor---does it have enough flow to sustain 600hp

 

www.gmpartsdirect.com has the lt4 conversion kit for $2,091.16

allot of people will tell u how u can get more power and spend less if u just go cam, and port/polish

 

My LT4 (non-hotcam) makes 311RWHP with a proper tune. This is through stock 48mm TB, stock manifolds, stock dual cat y-pipe. The only performance adders that a stock LT1 car would not have is the ram air intake and 3" cat-back.

I've seen plenty of otherwise stock Vette LT4s make 330-340RWHP with just the hotcam added to them. Granted the Vettes have a better intake and exhaust, but they are about equivalent to a cold air intake and cat-back on an f-body. Especially when you consider that most Vette Lt4s dyno right at 300RWHP and I'm at 311RWHP with ram air intake and cat-back.

Finally, I have seen dynos of guys with the LT4 "kit" and all the bolt-ons including LT headrs making 350+RWHP.

 

cool, thanks guys

 

Hotcam Kit, bone stock heads, good programming and boltons here and I made 340rwhp through the full exhaust (SLP single cats, ORP, Borla) and 355rwhp through the cutout in my ORP. With LT4 heads I'm fairly sure I'd be close to 420 at the motor through the full exhaust and over it running through the cutout.