I have a 1995 Bonneville SE with a bad motor. I am currently swapping the engine with 1999 SE engine and I notice the fuel injectors and fuel regulator are different. Do I need to use the injectors and fuel rail from my 1995 engine or will the injectors on the 1999 be okay? Also, the 1999 engine was using Dexcool antifreeze. Should I use the Dexcool or the green stuff my car originally came with? Thanks

You have more problems than that. Your 95 uses a 4T60E trans, and the 99 uses a 4T65E. Are you doing that swap also, or sticking with your current trans? I can't answer your question on the injectors, so you may just be prepared to try both if one doesn't work. I'd start with the 99 fuel rail and injectors.

That'* not going to be a problem with the 4T60E transmission. I am still using the 95 computer and wire harness. The harness connected to all the sensors except the oxygen sensor on the 99. But I had to swap the 99 exhaust manifold and air condition bracket because they did not match the 95, so that won't be a problem either. But which anti-freeze should I use the Dexcool or green stuff that my car originally came with...Thanks for your help.

When I swaped put a 99 engine in my 96 SE I used my fuel injectors and rails just because the seals on them were brand new and I didn't feel like replacing the seals on the 99'*. It shouldn't matter which ones you use they both should work find. As for the coolant you need to do a complete flush of the system. After that you can choose which coolant you want to use.