[Don 79 TA]

are you also using a stall convertor and some rear gears too? that cam probably wants like 2200-2400 stall

are you sure you set the timing marks up correctly?
you will have to adjust and play with timing since it's an aftermarket cam

also make sure you have at least 9.5:1 compression with that cam, it can be used with lower, but prefers higher comp

that cam should have some chop/lope to it in a 400, which should vibrate the motor, but what you are describing sounds excessive
was the distributor set correctly?
verified firing order
and is the balancer in good shape?

all these little things can add up
i'd love to hear how that cam sounds with your setup

to check what heads you have, get the code from the center exhaust ports

probably something like 6x

just some ideas on top of what the others have said
never assume, go verify