B4B manifold...again

[CHEVRIV]

Since installing a B4B manifold and 750 cfm Edelbrock carb on my 72 Riviera, we seem to have run into multiple problems. My current problem is while accelerating, the carb backfires non stop. It is fine at idle and cruising along. Taking off from a stop or putting a load on it such as driving up a hill it pops nonstop. Is it too lean? Suggestions? Also, with this new performance set up, should the timing be set differently? Thanks in advance for any help that anyone can give me.

[Jim Carmichael]

Since you had to remove the distributor to change the manifold you may have a problem with the timing or firing order. If the secondary circut is not getting fuel it will pop back through the carb as you described.