When I go over a bump (not big enough to bottom out), I hear a clangy thud from my rear suspension.
I can't seem to figure it out.

I've heard this before when I was running on GC Coilovers.
I thought the sleeves where causing it then.

Is there supposed to be something between the top mount of the suspension and the frame of the car?

They are metal to metal right now and I think i'ts causing the noise, even though theoretically there shouldn't be a gap since I've tightened the bolts.

Is there supposed to be something where the spring lies in the groove of the strut? I noticed my stock ones have a rubber type guard. I don't have one for my current setup.

Anyway... your insights please.

 

make sure the exhaust piping is'nt touching the bottom of the car.I had this problem with my old mustang when i dropped it and put on a 3 inch exhaust.