I have a 1995 Chevy Caprice that needs a
transmission. Will the transmission on my 2003
4.3 Chevy s10 or my 1998 GMC sierra 2wd 350
work or will both work in my 95 caprice
Nope, two totally different operating systems, the 95 is ODB1 and both the 98 and the 03 are OBD2 with the 03 being an updated version of OBD2. You will need to find an OBD1 transmission to make it work or overhaul the one you have if the case is in good shape.