Clunking under the car??

[ERA 626]

I did a fairly hard launch tonight then afterwards I felt a clunking sound under the middle to the rear of the car (ERA)
I put the car up on a lift and gave it a quick inspection.
Checked the u-joints on the half shafts, drive shaft all bolts, turned the wheels, I did not see any thing abnormal.
Then on my way home I noticed it again.
The sound does not sound like a gear sound sounds like a motor mount or a tranny mount or possibly one of the spax coil overs, any Ideas??
My ERA should be able to handle my little 427 right??
I am still getting wheel hop after tighten the rear coil overs and turning in the dampening screws how do I get rid of this wheel hop?? If anything my BFG's should just spin...