Just wanted to throw out there that I had a failure in the passenger side rear end mount on SPF #390. I am unaware if they upgraded the bracket on the newer cars. The metal they used on the mount is thinner then it should be or they should have added gussets to the mount (which I did). Mine sheared loose and actually had bent and tore the mount. This caused the rearend to slip down and the axle to hit on the frame, making a rotational clanging noise come through the roll bar. Just a heads up to do a visual inspection on your SPF's to see if everything looks good. I understand that this is not an isolated issue and it also has occurred on small block cars. Mine is all fixed and as much stronger then it needs to be with the new gussets.
P.S. Ray F. is a certified welder and did a great job fixing the problem. He said that he would fix others for a very reasonable price.
Jake 
SPF rear end mount problem
Threaded Mode
