Tried to install my new upper control arms tonight. Ran into an issue. Without any shims, the control arm hits the mount on the backside. Would probably need 3-4 shims for it to clear. Anyone else run in to this problem? What to do. Cut the corner of the mount? Just got the subframe back from the powder coater. Looks great, all ready to grind up

Hits where?
You will usually have some shims in there.

The housing around the control arm bushing closest to the firewall rubs against the control arm mount. This keeps the cross sharft from mounting up against the mount. For the control arm to clear, the cross shaft is about 3/16 away from the mount. If I need to put some shims there, it should clear. Otherwise it looks like I will need to grind the mount. It is only on the passenger side. Drivers side fits good.

I was looking at the DSE mounts at super chevy in Memphis. I think the speed techs are acopy of them. They were showing me a very trick bracket that welds in to replace the stock mount. They also have a bushing to allow more camber adjustment. If you have the bushing type or they copied that you might be able to change the bushing?

Joe

You will be ok, the rear allways has more shims on it for more caster. Use between 4 and 5.5 deg positive caster and .5 neg camber when you align the car.
The Speed Tech arms don't have slots or bushings like the DSE arms.