727 trans mount question

Yeah, I think the fat 273 insulators are the problem, but a 904 was stock and fit with these. Probably the girth of the 727 is still hitting somewhere under there. Ill drop it and look for the rub marks on the age old grease dirt coating that most transmissions get. Im sure itll be obvious where its hitting and I got a 5 lb clearance tool that should be able to massage any high spots. I might still slot those crossmember holes, seems it would help out considerable as the motor height is now fixed around my custom headers.