Will an engine from a 2000 Tahoe with a vortec fit into a 1996 Tahoe? I'm sure that has been asked and answered before so please indulge me.

 

If they are the same engine, they should. I cannot remember when the fullsize trucks changed over to the cast iron LS based engines.

 

do you need to change the wiring harness or ecm when swapping a 2002 vortec engine into a 1996 Tahoe?

 

Man I must have missed the Tahoe reference completely.

It really depends on what engine is in the 2000 Tahoe and if it is a 2dr as far as if it will swap over nicely or not. The Vortec 5700 (L31) was offered from 1996 thru 1999 in the 4dr Tahoe and only in the Tahoe Limited (2dr) in 2000. The LS based engines (4.8L - LR4, 5.3L - LM7, & 6.0L - LQ4) took over for 2000 on up to 2007 and were very much different than the earlier Gen 1 small blocks. This would not be a direct swap, but likely can be done with a lot of work.