I have a 5.3 LS from a rollover wreck 4x4 suburban and also a 4l60e from a 2wd van I want to use in my 63 nova wagon project. I wonder if I need to change anything in harness or ECU since old trans was 4x4? Also, 4L60 e is from a Vortec Throttle body engine. I am new to LS engines (but built many small and big blocks) so any help is most welcome.