Cam specs

I will try and explain some more of the specs I wasn't able to add last time. I have been trying to get more knowledge to better help my self in these situations. I apologize for the intermission in between my postings. With that being said;

a 625 weber is being used as the carb on top of a dual plane intake. The heads have 2.02 valves. Cam is .281int .296 exh, dual exhaust, pipes are 1 3/4 in-2in
7 1/4 in rear end and a 904 transmission the pistons are not high performance, lower compression. mechanical fuel pump.

My problems seem to be focusing around this carb. I am not sure if the secondaries are working correctly, and sometimes when it gets to its full position on the fast idle cam while warming up it sometimes stalls when I attempt to kick it down. I read in a book that 625 may be too much for a 318(328) and the book says a more realistic number for a regular 318 is close to 550cfm. The carb had a spread bore to square bore adapter(hope this is the name) underneath it. It was in bad condition and the plates seem to move freely without it.

I have read it could be a vacuum leak or a too low of a warm idle speed. Or if it my cam not allowing it to idle at a lower rpm.

I appreciate the time to help me do some basic troubleshooting.

Thanks