So I just recently got the engine back in the car after rebuild and paint. Its been nearly a year since the car was driven last. Engine work was mostly top end (new cam, lifters, rockers, springs, pushrods, timing set). I'm using the same carb, distributor, and ignition as before rebuild and it all ran fine previously. Spec's below.

I primed the oil system and ran a good break in cycle, didn't notice any problems. On the first drive, I got a lot of hesitation on take off and misfire. Even when running a constant 40 mph on the road, I get a random misfire. Happens more on acceleration. Also seems to get worse as the car heats up.

I started at 10 deg initial timing, and have since played around betwen 6-12 deg and timing doesn't seem to have much influence.
I'm also noticing at idle, it won't keep a constant RPM. It jumps around 30-40 RPM at any given set idle speed. I was trying to adjust the mixture screws on the carb and can't get an accurate feeling of an RPM swing because its jumping around so much.

I checked the plugs after the first drive and they seemed a bit black and had a little oil residue. Not sure if its related and I'm hoping the slight oil on them was just from break in before seals and rings found their home. All 8 seemed very uniform. Also not sure if this is related but I have very low (~5 psi) oil pressure at idle but it jumps up well on accelleration.

After searching the archives here, it sounds like I may have a vacuum problem..causing RPM to fluctuate? Would this be related to the misfire? I don't see any leaks or gaps around the intake and the only vacuum connection I have at the carb is for the tranny (no vacuum advance distributor or power brakes). To check vacuum, do I have to check at a port in the intake or can I check one of the unused plugged ports on the carb?

Also I was going to check compression across the cylinders but haven't gotten that far yet.

Any other suggestions??????

Engine specs-
1967 400, 670 heads with dished pistons to lower c/r to ~8.6
Summit 2801 cam
performer intake
MSD ignition & distributor
Edelbrock 1910 quadrajet