small block wont idle

hello there, first off I should mention that I'm a generation Y'er so I don't have the kind of carburetor experience that you old folks have :).

Anyways, here's the situation. I have a 327 small block that i put in my 87 Fiero (yes its actually a common engine swap). I've got an edelbrock thunder series 600cfm just under a year old, with a new edelbrock performer RPM cam (broken in properly with plenty comp cam break in oil additive) and intake manifold. I set valve lash while the engine was running, I was pretty cautious of overadjusting. I had a mallory uni-lite distributor in it for about 125 miles, until after about 3 module failures I went with an MSD ready to run distributor. Installed it and about 15 miles down the road a carb stud went loose and developed a huge vacuum leak, it would pop and die. I replaced the carb gasket and reinstalled all the carb studs with loctite on the threads into the intake manifold.

Brings me where I'm at now, it will only run by reving the snot out of it then will idle for a short second afterward. I know you guys are gonna hate this but I haven't got the exact timing because of how much of a pain it is to do on this car (have to use a timing mark on the flywheel underneath vehicle, balancer is literally stuffed in the frame rail). I been just trying to find it with moving the distributor and observing a vacuum gauge, unfortunately it doesn't run long enough for me to see anything more than 5 inches mercury. I thought i had it too far retarded and it runs with reving solely because of the vacuum advance, but i adjusted the timing slowly counter clockwise and all i get is it running worse. I got 6 psi fuel pressure, timing was set to where it ran fine prior to the vacuum leak. I replaced the coil just in case, no change. It's a brand new dizzy, under a year old carb, brand new blaster 2 coil. all vacuum lines are fine. Later today I'm going to spray carb cleaner around the intake manifold, and double check the ground for the pickup coil on the distributor. I did mess with the air/fuel screws in the front of the carb, would this cause the situation I'm in? they're only about 1 1/2 turns out, pretty close to where they were before to my recollection. And the only way I can get it to idle is if i turn the idle screw in so that the carb is at about 1/8 throttle. If all is good where do I go from here? thanks in advance.