1991z28ragtop

I have a Procharged 383 with a T-56 which tore up the bushing on the front of my SLP adjustable torque arm. SLP no longer sells the bushing so I called BMR and ordered a new one. (BMR and SLP torque arms are identical). I received a new neoprene bushing and went to install it and it didn't fit. It appear the clamshell bracket for a manual transmission has more than one style. I'm aware the manual and auto clamshells are different but this manual clamshell which I got from a 5 speed doner car when I converted from auto to manual worked with the SLP bushing.
My question is are their more than one clamshell brackets for a manual trans? the mount fits on the side toward the transmission but the outer side of the clamshell bracket does not form to the mount. Any help would be appreciated.