what 4 speed auto transmissions can i use? 46rh etc
The problems with Mopar OD automatics:
I believe you can "work around" the RH series which stands for HYDRAULIC
The RE series either must have a computer or can be converted to "all manual" and then manually switch the OD
The 46 series (A518/ 727 based) will NOT fit an A body without serious floor/ tunnel work
the smaller A500 / 904 based (42/ 44) will fit with "serious" crossmember mods, but you can get by without cutting up the floor. There's been a couple of "serious" threads here on FABO
At least one member did a write up adapting the GM 200R4 / 200-4R into an A which does not require floor mods
