Transmission Recommended to Run Behind Built 360ci Engine in a 63 Valiant
As I understand it, if you use a 65 V8 904 with your earlier valve body, you can retain the pushbuttons. The 65 still uses the ball and trunnion joint but back in the day if they'd hold up behind a Max Wedge, it'll hold up behind a 360. Of course it would still need to be built and as Mullinax95 said, Dynamic can do it all for you.
The converter for a 904 (727, too, probably,) has a "button" on the front that indexes into a recess in the back of the crankshaft and it supports the shaft that the converter rides on; considerable weight.
That button was made a larger diameter in 1967 or '68, and the shaft the converter rides on was, too, so in order to run a later-model converter (and, tranny) you need this larger hole in the back of the crank..
Your crank probably already has the large hole.
On the other hand, if you want to run the smaller-buttton converter (early model for an early crank) you need to have a transmission with the smaller shaft,
and an early crank, OR a bushing to make up the difference in size between the converter snout (small) and the crank hole (large.)
I have read that those bushings are available, but since your crank is a late model with the big hole, and the later transmissions are inherently stronger, why not go with the later tranny and converter, wherein everything matches?
The worst thing that can happen is that you might lose the pushbuttons, but there are lots of good floor-shifters available.
It might even be possible to adapt the pushbutton valve body to the later case; I dunno...
Good luck!!!:cheers: