The difference is that the CA bell housing must be shorter my first hi stall converter was from a VL it needed the face machined to be use able not a big thing for a competent converter repair shop take the box out sit it on the floor run a straight edge across the front of the bell housing measure in to the mounting bolts , gives you X distance now do the same at the engine run the straight edge across the rear of the flex plate and measure towards where the gearbox meets up with the block give you Y distance , now what is the distance of the 2 it will be seen clearly on a piece of paper you also want around a couple of millimeters of free play as you want the converter to come towards the flex plate when doing up the bolts as if not it will kill the thrust bearings in your engine real quick , always allow for this as one converter shop did not but I checked it before installing by measuring as it is no fun wrestling a gearbox on your back only to have it in and out 5 times for someone Else's mistakes . hope this helps

Nick.