At wits end with a motor problem Help please!

[Jefe]

Ok here goes...its a 307 in my 68 daily driver. I just replaced the head gasket on the drivers side head because of an oil leak that I am buttoning up. Fixed the leak but now after everything is installed it runs great and idles ok....but just off throttle there is a dead spot and if I crack the throttle quickly it just bogs itself down and wont regain unless I let off the throttle. Heres what I have checked firing order/timing/carb been rebuilt(was running great before all this)/vacume leaks/valves adjusted fine on the drivers side/good amount of fuel. It wasn't doing any of this before I changed out the head gasket. I am at wits end...please help! THanks guys your the best on the net!

Douglas.