Q: Can I swap a 97 4.3 with a 94 4.3?

Hi there. You can change the engine block, but the cylinder heads will not match up. The cylinder heads for a 94 was made for an intake with a throttle body and injection in the throttle body where the 97 was made with a throttle body with individual injectors to each cylinder. The cylinder heads won’t bolt up to intake manifold. If your swapping the engine out, make sure that all of the sensors are able to be installed onto the engine. You can put any V-6 or V-8 GM engine with a 4L60E transmission either small bell housing or large bell housing into your vehicle. If you need further assistance with your engine swap, then seek out a professional, such as one from Your Mechanic, to help you.

Hello. These engines can be swapped, but it is not an easy switch over. These engines technically are the same size but they do not function the same due to a design change. You need to use a 1996-2000 4.3 in order for it to work directly. You can use the transmission out of any of those years and they will work fine. If you want this to be an easy job it is important that you use the engine VIN from a similar truck.