I have a 1999 gmc savana 1500 5.7 and i just replaced my transmission and it was a 4L60E. So yours should be the same.
A 1999 Ram automatic uses ATF+4.
If it's an automatic, dextron II.
The 1999 Chevrolet K1500 5.7L is equipped with a 4-speed automatic transmission. The transmission model for this vehicle is the 4L60E Hydramatic.
4L60E Transmission
What type of transmission fluid is used in a 1995 dodge ram 1500?Read more: What_type_of_transmission_fluid_is_used_in_a_1995_dodge_ram_1500
4L60E OR MAYBE A 700R4
That would be the 700R4
Dextron II transmission fluid.
ATF+4 if its a automatic transmission.
Go to Chrysler.com give your VIN ask the question they will respond quickly that's how I found out what rear was in my 1999 Ram
DEXTRON II automatic transmission fluid
The automatic transmission uses ATF+4