Gmc 1500 5.7 motor
 

What is the proper operating temp of my 1993 5.7 motor? What is the best thing(s) I can do to improve my 4L60E transmission performance? Cooler? Shift kit? Other little goodie mods that make it work snappy.

Depends where you live. I think most run a 185 degree thermostat, where here on Alaska I like to run a 205. And are you sure it's a 4L60? I believe that was used only on the newer engines.

My research shows it could either have the 350 tranni or 4l80E

Average operating temperature of your 5.7 should be 195 to 215

yea thats more along the right lines Glenn. I know the 4L60 is wrong.

195* F is the OEM temp for the T-stat.
1500 and LD2500 had 4L60E while HD2500 and up had the 4L80E, however if it was a 1500 with 6.5L TD it had the 4L80E. 1993 was a transition year for the 4L60/4L60E so check and see if there is a TV(kick down) cable on the TBI unit. If you have a TV cable it is still the 4L60 version.
The TH350(3L60) hasn't been used since the early '80s.

We could use some more info on the truck and what you are planning on doing with it. Also is there any issues with it that you are trying to correct with transmission mods?

Thanks for that Diesel Dan
Obviously your source is much more detailed and reliable then my source.

I was still working in the dealer scene in that era.
Even with that I can't recall exactly what models did/did not have the "E" series transmission. IIRC the 4.3L CPI motors had the E-version but the TBI motors had older version. All 4L80s were "E"(electronic) since their introduction in 1991.

The proper temp is 195*f and 1993 was the last year of the 4l60.