backfireing through carb at low rpm
i have a 355 chevy that is backfireing through the carb under 3000 rpm. i have a 770 holley carb, i have had the valve covers off there is not a flat spot on the cam or a hung up valve. good compression. i do not know what the cam is though. it also has low vacume coming off the carb. anyone have any suggestions where to go from here. it runs great over 3000 rpm and idles fine. has new plugs and wires. just pops when i get on it at low rpm.