Magnum mount issue?

The only thing that elads me to think mount os the like is it sound slike the engine is beating on the floor boards it thuds against the car like a header rubbing but they arn't and they are TTI'S all the clerances look nice the car is pretty smooth at 2000rpm but 1500rpm is terrible and 2500rpm is getting rough.

Still working on it witht he engine builder but the numbers are supposed to be all great. He doesn't love my Professional Products balancer though

Just getting stumped and looking for all suggestions