I have ICL at 106, LSA at 110, Duration at .050 is 240 and 246. I don't see a spec for duration at .004.

More specs:

duration at .006 283/300

Gross valve lift is .508/.511 but with 1.6 rockers that .542/.545

Comp cam claims I shouldn't have issues with vacuum but I told them at 10.5:1 compression. The seller told me that's the compression but I am trying to research the piston installed and head CC to confirm that. I have not run a compression test yet but I will be doing that next.

Hrmm... maybe you have a vacuum leak somewhere. Still, that's a big cam for a cruiser. JMHO

My 2000 Z28 that ran high 10's - full weight, drag radials, through mufflers... did so with a 228/236 @ .050" duration cam in a 347" LS1. It had great manners and pulled 17-18 inch/hg of vacuum. (factory cam was 20-21 inch/hg for comparison) It was a Crane cam, I had a Comp Cam in it previously that made less vacuum (12-13 inch/hg), made less power, and had lots of cam surge unless I kept the RPM up. That cam was 238/242 @ .050"

I could go on about cam stuff, but I feel we need to figure out your vacuum problems for now.

My main concern right now is getting the brakes improved. If indeed the vacuum has always been low (when previous owner first built the motor-which I am trying to find out) then I can focus on getting a vacuum pump or hydroboost. However, if indeed there is a leak or some other mechanical issue, I’d rather resolve that issue and not put an expensive bandaid on the problem. Other than a leak at the carb or manifold (I check hoses and no leaks), what are some other possibilities?

What is the best way to identify leaks at the carb ? and intake? I don’t want to start ripping things off.