You need to consider is the motor trany setup correct. If the cam specs and the converter match up then consider it a tuning issue. If you have a hot cam and a factory stall, then it will never work. Unsprung weight is unsprung weight and no matter what gears you put in it, it will bog the second the motor hits the load. Kind of like letting the clutch out too early in a stick car and blaming it on the tuning.
If its a tuning issue then I have usually found the pump shot to be too aggressive. Try backing that off and see if it improves. Also try moving the timing around to see if it improves r not. This takes experience and some go one way when others go another. Your call.
The most important thing I have learned about tuning is One change at a time. Never more or you will have no idea what did what.
