stall

Ok guys, my first thread. I've got this magnificent 74 nova with all original mechanics. the recently rebuilt rochester dual jet stalls out pretty bad when you romp on it. I suspect a vacuum leak, I just haven't hunted it down yet. My question is, if I replace the intake manifold gasket, what...

I have two 2008 Chevy Tahoes (99k & 112k) and both have the same problem, I had taken it to dealers and regular shops, but no answer. The problem is: vehicle starts to shake/jerk and sometimes stall. It will restart without a problem. it mostly happens while slowly pulling out of parking...