440,
If you are thinking about putting the 440 into a vehical that had a slant 6 or a small block then you will have to change the motor mounts and tranny cross member. Also the "K" member will have to be changed as well. This is not a hard process. If putting it into a vehical that had a slant 6 in it, then keep the springs and shocks for that vehical in the car. The weight from the 440 will give you a good "stance" on it. Alot of MOPAR racers used slant 6 shocks and springs for that look. Go to this link for help in this....

http://engine-swaps.com/

They have helped me in the past with everything you need for the swap.
Also, the small block MOPAR had a different bolt up pattern for the bell housing concerning the tranny you mentioned. The slant 6 had its own pattern. the 318 thru 360 had its own. 383 thru 440 had its own and the 426 hemi had its own.
So the small block tranny will NOT bolt up to a big block. I would try to keep the trnny/engine combo together on the 440 you have. Bolt it in as one complete set.
I hope this helps.
DCON