Not exactly. LT4s, in spite of their factory rating, are really closer to 350 HP in reality. And these kits also include the Hotcam which bumps it up further. But still no, LT4 heads, intake and the HC are not going to provide anywhere near an additional 100 HP w/o some other mods too. I agree, having LE, Advanced Induction or some other specialist redo your LT1 heads and provide a matching cam will get you more than the LT4 kit and for less money. For example, I believe the LT4 heads flow right around 240 cfm~ on the intake side at .500" lift. My modified LT1 heads now flow over 270 at .500". They also have had 2.02-1.60" valves installed. For my head and intake porting, oversized valves, ceramic coatings on the valves, combustion chambers, inside the exhaust runners and on the bottom of the intake, I think it was right around $1500 for everything. This didn't include valve springs, I provided my own, the 26918 CC beehives. And although I could utilize a lot more cam, I still use the humble old Hotcam. In spite of that, this engine still puts down some very impressive numbers, both on the dyno and at the strip.No need to do a LT1 to LT4. You'd get 30 HP. That's what the LT4 was rated at anyways, 330 with a slightly higher compression ratio.
Go with Lloyd Elliot for the LT1 engine. From what I've read and heard he does top quality work for the LT1 engines.
Just to clarify, Nearly all LT1 heads chambers CC out at around 54cc's(give or take) ....most LT4 heads chambers are slightly larger (about .4cc larger) ......the LT4 engines slight compression bump came from having shallower valve reliefs in their pistons.......Joe:thumbsup:agree, for the price of this kit,
i got a nice AFR with 185 cc, 2.02, 1.6 valves. CNC ported.
plus 54 cc chamber (the LT4 size).
that way you can be a modefied LT4....
if you want to pay.., then pay it for some thing gives you what you are paying for.