Engine Plan...

[Mark B]

I wanted an LS1, but cant afford one.
So I am going to build:

-GM Performance Parts 350 HO Short block
-Vortec Heads w/ Comp Cams beehive springs
-GMPP Roller Rockers
-LT4 Hot Cam w/ all the hardware to make it work
-Holley Stealth Ram Intake

Im shooting for 400hp.

Car Craft did pretty much the same engine and got 401hp so I think I should be ok. What do you guys think?

[zz4camaro1980]

I know that the LT4 Hot Cam can support 400 hp easily. Im running it with 1.6 RR in a ZZ4, it came dynoed from GM with 395 hp. Now im pushing a little over 400 hp with some extra goodies. I dont know much about the vortec heads, but as long as they flow 200+ cfm you should be all set.

[94Z/28]

Box stock vortec heads wont support the lift of that cam. I think max lift on a stock vortec head is like .420 due to the high valve guides, but there are places that modify them to handle more.

[Mark B]

I all ready know about that problem. I have a local machine shop that will mill those down for me. Normally the spring seats have to get cut too, but I am getting around that problem by using the beehive springs.

[fastTa]

Some 96+ 3/4 and 1 ton trucks came with Vortec iron heads that had a specificaly hardened exhaust seat that kills low and mid-lift flow. This can cause a 20 percent of its flow loss at as little as 0.120" of lift. These had a casting number of 10239906 and should hence be avoided.

Vortec heads actually outflow LT1 heads where it counts even though they use virtually the same intake runner and exhaust port. You will easily get 400 HP with the hotcam and roller rockers.