Advice re: 1990-1993 Blazer/Jimmy

91 and 92 will have the 500R4 transmission, 93 will have the 4L60E (electronic version)

with either one, bypass the cooler in the radiator and go with as large an external cooler as you can fit behind the grille

do fluid and filter changes every 1500-2000 miles for the first 10 l, to get as much of the old fluid out as possible

Dex 3 is good, use a bottle of 'Red Lubeguard' every other change

Been on vacation a little too long there Gary? Wasn't it the 700R4?

Listen to this guy on tranny stuff, he re-builds them for a living. Keeping tranny temp as close to its designed parameters is always a good thing.

shit

The CPI engine is easy to identify. If the throttle body is facing the front of the truck instead of sitting ontop, and the intake looks like a big, black, six-legged spider, it's the CPI engine. They do have a nasty habit of developing a leaky injector system though, so be warned.

You could also check the eigth digit of the VIN. You want the "W" engine. "Z" is the older TBI engine.

Most trucks of that era will have about the same rust trouble, all else being equal. Watch out if the truck has a tailgate mounted spare. Where it mounts to the quarter is a notoriously bad area.

Torsion bar mounts are a weak point (cheap to replace though). Front end parts tend to wear quickly with off-road use (probably no more than any other truck though). Digital gauge clusters (if equipped) have a nasty tendancy of going blank. Wheel wells are horribly shaped for oversize tires without fender trimming or large lift.

Don't take any of this as a knock against the trucks, I love my '91. I couldn't kill my 4.3L if I tried. When it's time to junk lil Jimmy he'll most likely drive to the scrapper under his own power. Just trying to be fair. :o)