Originally Posted by barr5150
I just realized there's no shifter linkage on the 233!! Must be electronically shifted? Looks like I'll be keeping my 231!
Yes, the NP233 is "3 Button" electric shift. The NP231 is manual shift, I own a Blazer and these cases unfortunately do not have great after market support.
Some 1st gen S10s and Blazers had an "HD" case in them. This included a 1.25" wide chain and 6 Planetary gears, they also had fixed front outputs. These parts are interchangeable between 1st and 2nd Gen cases (Note: NP236 is a VERY different case (and junk)).
I've read there is some interchangeability between the 231C and 231J cases but, I'm not positive on what exactly.