Help convince me to go BB in my Duster?

I did not read this entire thread so someone may have already told you this. The only way to run a 904 with a big block is either with an adapter plate or by cutting the bellhousing off the 904 and installing a JW ulrabell bellhousing 904 to big block. Same thing if you want to use a 727 from a small block. The small block and big block have different blot patterns. Your best bet is to get a big block 727.