i dont think a 92 would work beacuse i do not beleive the 4L60E was availible in blazers, but if the 93 has the 4L60E and has the same drivetrain(both vehicles being 2wd or 4wd) it should be fairly straight forward. if you stick around a bit someone with a lil more knowledge will chime in and give you a definite answer.

 

You do not want to go backwards with the 4L60E. Newer only! Modifications have been made to the transmission over the years, some of which are required to safely operate in your truck.

 

I think it might benefit you to drop the pan and re-check everything that could have been dinked with during the fluid change.

 

We've known the tranny has been going for awhile, there were codes in for things slipping, it was just a matter of time. I'll be moving soon and will no longer have a free mechanic (my dad) around to fix things. The only real option in this specific situation is replacement and my dad knew a friend with a 92 or 93 for cheap.

 

Is it actually slipping?? The 'code' for slipping could just indicate that your torque converter isn't locking properly at highway speeds. That will generate a trouble code and increase the line pressure that gives you a very firm and noticebly different 1st-2nd shift. I've heard that this could be caused just by the valve body within the transmission. I have the same problem and did a little searching on it. Your problem sounds more and more like what I just described...