Still won't Idle

OK, I checked the few things mentioned above. The PCV valve seals and is hooked up. The engine will pull strongly clear up to 6K with no problem. I may not have clearly stated the problem as correctly as I should have. With the boosters swapped which eliminated the accelerator pump the engine runs great but has no squirt to get it to transition. In this configuration the thing will idle perfect with the screws out maybe 3/4turn. My figuring is if it had a major vaccume leak it would have to have the screws way further out. I replaced the power valve and it still dumps fuel thru the primary booster when correctly assembled causing it to run way rich down at idle. With the excessive fuel it won't idle.

If the primary booster is incorrect will it cause this? YES!!!!!!!!!!

In an effort to help some one else out I just swapped a primary booster 6 D2T froma 480 cfm carb and the thing will idle and transition with accelerator pump, fabulous. The booster that was in it has a number of 4K2D? and as I remember the carb ran a 351 windsor. So at any rate with the forums help and some testing and fiddeling I have the car running well. Thanks all.

I have one other question, how are the booster numbers deciphered? First number maybe a year and from that point on, a size must be indicated.......From the quick run I just did it may be still a tad rich as I could not get a distinct change with the air screws as well as I hoped. Can some one tell me the correct number booster I need or should be looking for? Can I find one from a 2v carb? Engine fresh and I would consider it to be set up comparable to a 271hp with similiar cam, Cobra manifold, stock heads, headers and this carb.

Thanks again.