Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
Hi there, I am Cam. Can I get your first name? "Simply swapping engine is not going to work you need to swap everything to accommodatee the 2005 engine. IF it was me, I would take engine and transmission, both modules and then once installed, program the Vin of the 2005 in the BCM of your 2003, do a theft relearn and then your engine and transmission are matched to the BCM.