I see 2 problems. The first one is what everyone else mentioned and the Clifford manifold is just not going to work well on a stock 292. The second is how the fuel is being handled by the carb. Since it came off a small block Chevy that narrows it down to something between a 265 inch and a 400 inch engine not even considering any performance work done to it so is the carb "as is" as it came out of the box, or has it been tuned by the previous owner? Either way you need to begin with the factory Edelbrock set up and then follow their tuning charts in the manual. The manual can be downloaded from their web site.
Generally speaking from all my experiences with those carbs about all you need to change on the primaries for a stock 292 on a decent manifold is the metering rods and maybe the springs when the rods are right. But if the carb has been changed by the previous owner you really should go back to square one before attempting any tuning because the booklet begins at that point. I have run the 500 on as small as a 200 cube Chevy V6 with only rod changes and of course secondary jet changes.
Heat might help the Clifford somewhat but I don't believe it is the real answer in your case.
