No gas -when starting cold

It sounds as though you may have two separate problems. Since you have changed the carb. so many times I think it's safe to assume then problem lies elsewhere. Assuming you don't have some kind of bizarre intake manifold, I suspect the cold start problem is either due to a vacuum leak(s), or it is choke related. After pumping the gas 6 to 7 times the engine should try to start without the need for manual priming.

The problem with fuel leaking past the float valve(s) is being caused by either dirt in the system or excess fuel pressure. The maximum for most US made carbs. is around 7 to 7 1/2 PSI. If your fuel pump doesn't exceed this pressure there's no need for a regulator. Good luck...Al English

I have a edlebrock carb and I think a replacement stock / high volume fuel pump. I put it on myself. Why would it start after it is warmed up if it had a vacuum leak when it was cold? Make sence? If I switch out the carb and put the holley back on it that I was running before I switched to the Edlebrock it will definately leak into the back bowls after only a few seconds. Took the back bowl off and checked for dirt and found none.?????

The way to check the fuel pump pressure is with a gauge. Put a "T" in the fuel line & watch the pressure while the engine is running.

An intake leak will be more apparent when the engine is cold, as under those conditions the engine requires a rich fuel mixture. The extra air added by an air leak causes a leaner mixture. When the engine is up to temp. the engine can tolerate a leaner mixture(up to a point) so the effects of an air leak may become less noticeable as the engine warms up.

Ignition problems can also be more obvious when the engine is cold. Check your coil, wires, cap, etc.

I have also seen cases where incorrect cam timing can cause hard starting and also require excessively rich starting mixtures.

Hope some of this helps...Al English