Now I have installed sbc into alot of different cars and usually I can troubleshoot this problem granted I am not completely done with my investigation but, I figured I would prompt the boards and get you guys prepped to come up with some good answers.

I've been a little lazy about this last install. Didn't take any shortcuts just kinda took my sweet *** time. Plus I've been working with a broken ankle and now I gots a few probs now.

The engine is kinda hard to start when it's cold. I gotta give a little pressure on the pedal to get it going. then I gotta stay on the pedal (fluttering) for about 10-15 sec. before it'll stay running on it's own. Then the engine vibrates. When I say vibrate I mean a constant vibration of medium significance. Not like a surging vibration where it surges to the side violently about 2 times per second. but a steady more mellow vibrating moving side to side.
It gets a little better when the engine warms up but, not by much. The funny thing is that performance doesn't seem to be suffering at all. Half throttle will give me a loud chirp. full throttle will light'em up.

The timing has been set to 6 BTDC because this particular engine is from an 80-84 truck according to casting numbers. (350 4 bolt punched 40) however I have it in a 91 RS. in which the ECM expects 0 TDC. I was wondering if this could've created a conflict. I don't want to risk detonation by setting it at 0 just because the ECM wants me to.
Also I wasn't able to thread one of my smog pipes into the manifold and it cross-thread on me (#5 cyl) I said F it for now but, was wondering if this could be causing my problem as well. I did have a code pop up on me. I will scan it today and see what I get. I will keep you guys posted. Just wanted to get the wheels turning now so that when I come looking for suggestions they will be here. This should also give you guys some time to think about it.

Dig In and Thanx in Advance

 

the fuel mixtures are probably off. I have the same problem. The engine runs a tad unevenly at low throttle loads and at ide because its way too rich. Once i get past that, its fine. Runs great at higher loads. Id also suggest bumping up the timing if it has 72 cc heads. They like alot of timing and it really helps on startup. The easy way to check for detonation is to hook a scanner or software data logger up and check to see what the knock counts are. If your only getting a few that are evenly spaced throughout the rpm/map band then your fine. If your getting alot all over or in one spot then you should back the base timing down.