Hello all I am having trouble getting my Velle to idle without backfiring up through the carb. Here is what has happened:
I have a stock 350 with a new Edelbrock 1406 4bbl new heads that have been checked new 2.02 valvs and crane roller rockers. I have checked the TDC twice to make sure everything is correctly installed and that the rockers are adjusted properly. The carb is new and nothing has been adjusted save the idle speed screw. It is set right now right at the point of contact with the throttle linkage.
it will run if I turn the distributor counter clockwise but it races badly and pops through the carb when I adjust it clockwise the poping reduces and the engine slows a little but too much and it dies.
Is this because the Idle speed screw is not set correctly?
If i do engage the screw and leave the dist where it dies it does not start.. it acts like it wants to but it does not want to kick over.
I dont have a timing reading as I dont want to keep it running when it is popping through the carb the way it is. please help

The first thing you have to do is invest in a timing light. Once you have the base timing set, everything will revolve around that.
The popping back through the carb can be caused by a lot of things, including improper timing. But you need to check and make sure the spark plug wires are installed in their correct firing order. You may have also installed the distributor 180 degrees out of time. You need to make sure it was installed with the timing marks at TDC of the COMPRESSION stroke of number 1 cylinder, and with the rotor pointing at the number 1 tower on the distributor cap.
Was the engine running good before you installed the manifold and heads?

It sounds like you also have a plug wire crossed.(check # 5 & 7). It also may be off one tooth on the distributor.Try advancing it one tooth.