Re: new ZL1 build suggestions. Help needed!!!
I am nearing completion of the same zl-1 motor with 850 block. You have the earlier one judging by the blue plugs and label. I know from a local source ( I live 15 miles from Schwartz machine that finishes this block) that at one point they had a line bore issue, check that. Mine was perfect the motor builder says, the cam bearings were a little tight, these things are a piece of jewelry, they should be for 5k!
You need to run studs and the Mls gaskets, stock Melling m77 pump, no high volume, in a Camaro, you need to modify the stock windage tray/oil pan baffle.
What heads? Original 074 will end up being $2,500 done, good cores are getting hard to find, no more than 1 weld repair per head is recommended. The 074 heads have porosity issues and big roller springs are not good, I am running a flat tappet solid.
Do not bore these out if you don't have to. The thinner the liners, the more heat. Buy scat forged crank and rods over eagle, mine were right there, diamond pistons are the answer if you want a specific compression. I am only going with 11.60, it will run on pump gas, stock was 12.5.
The cam will then determine your bleed off, the original zl-1 cam is to much and lazy for the street, the look at the l88 cam, especially if you are running exhaust manifolds.the 198 correct intake is pricey, the 163 is virtually the same except the plenum divider is cut down on the 198.
Build a Holley 850 4781 ( if you need a stock look like I do)with the 198 intake, stagger jet it like the 4296 Holley that it came with. Stock curved distributor with a pertronix 3, initial at 18-20 degrees and mechanical advance 20-24. The guys run 44 degrees total at the track, no vacuum advance to kill bottom end power, timing curve should be slow, total advance all in above 3,000, otherwise you will need tires real soon.
Keep us in the loop