itscompton, a 904 tanny pan is a square with a triangle slice cut on a corner. The 727 has a side buldge and isn't exactly square, but close. The healthyness of the tranny is something of a unknown and is key on how much power it can handle. Pep up the engine? Fine. When time and money allows, you can do the whole thing.
I don't see how "Not to go against rumble, " works in there, but. I was not suggesting the use of a 727, but just said a driveshaft shorting would be needed if used.
The 904 has a lower gear set in newer years. To new and it'll be a lock up tranny. Different converter again.
Since the 360 is externally balanced, you'll need a weight on the converter or the flex plate. I went with a B&M balanced flex plate,
Thanks for posting this Moper. I did leave that out. (DUH!)
And truthfully, you can use some wahsers to make spacers and run the 318 steel bracket if budget says you had to. I did it for years on several cars...