What transmission is in a 1995 Isuzu npr?

If you have an automatic you probably have a 450-43le transmission. If your tranny goes it it usually cheaper to replace it with a GM TH700-r4 There are adapter kits available. If you have a manual there are three choices in Isuzus MBP, MSB and MXA. You need to call a dealer with your VIN to be 100% sure.