Im using the aftermarket tubular AT mount for supporting my 700R4. Based on what I'm hearing I should opt for a similar tubular engine mount with side mounts.
I understand what you are trying to do, and the advice for the modern side mounts is a good one. I was just wondering how the original 265 w/automatic transmission was mounted in the rear so as to illustrate exactly why using a modern side mount setup is such a better idea for what you are trying to do.
Carl