Thanks for the reply Rob!
I figured someone on this site had swapped motor mounts in a Monte?
If memory serves, I did the "X" measurements 20yrs ago and it was close. I'll do it again to be sure.
I bought the car secondhand in '89 with a 305. Being that it was an SS I didn't think they cam with a V6. I could be wrong.
I guess I'm going to have to drop the control arms to get inside the frame to see if I can loosen/replace the motor mounts. I have a new set of motor mounts for a '75 Camaro. Any idea if they are the same?