289 with a 600 holly nice cam headers duel piont dist. with stock coil dist. has mechanical advance { no vac.} on take off it hesitates but once it rolls it runs GREAT its bolted to a automactic trans can anyone help thanks

It could be a lean spot in the carburetion, caused by the secondaries opening too quickly (if vacuum secondary, a firmer diaphram spring will correct this)

Also, the accelerator pump may need adjustment, to deliver a bigger squirt of fuel. I recall the plastic accelerator pump cam has 2 positions, and can be moved from one to the other for adjustment. Also, a larger set of 'squirters' can be installed. They screw in just above the primary barrel venturis.