904 to 727 swap compatability

I'm getting ready to replace my 904 trans with a 727 in preparation of upgrading my 273 to a 360....and my rear from 7.25 to 8.75 suregrip.

Spoke with a few vendors and another A-Body member. One vendor says the trans will swap over to the 727 without any modification to mounting. I know I will be looking at resizing my driveshaft,

The other vendor and A-Body member saya I will have to modify the trans mounting to accomodate the 727 as the 904 mounting is different. :banghead:

Again, I ask for your wisdom. I'm learning as I go....and can't seem to find an answer to this one.

I'd like to get that 727 ordered as the 360 should be ready in a matter of weeks.

Thanks in advance for your help.