I don't think the 327 was available 'til '66...at least in 10's.
I've had a '74 250, a '66 327, and back to a 6 in my '65 C10 and never had to touch the motor mounts, which are bolted to the frame.


If you can't fix it with a hammer and screwdriver, you need a bigger hammer.
1965 Chevy C10