I am sorry, for some reason I thought you wanted to replace the injectors, but I was getting it confused with another thread. Napa has a complete set of injector and fuel rail o-rings, which is what I ended up going with. It was special order for me, but that just meant I had to wait a few days to get it in store.

More Information for FEL-PRO MS949181 FEL-PRO Part # MS949181 This is the LIM gasket
There is no listings for an UIM gasket, so I believe you will just use a gasket maker on it. Not sure if the coolant fittings use orings or not, but you will see that when you get it apart.
There is a small heater hose that comes from the area on top of the water pump, curls around, and goes under the alternator, to the fitting I mentioned. You pull the alternator off, it will be staring right at you.

My thread on it: https://www.gmforum.com/buick-172/l2...cement-303150/

I don't see a throttle body gasket listed either for you. But be ready to scrape gaskets, as I believe the UIM for you is goop sealed to begin with.

Look through my list, and if I think of anything important, I will add to it.

Thank you Randall. Unless I had a bad injector would there be any advantage ti replacing the injectors? I hate to replace parts for no reason

You could get flow matched injectors, but in general, if it'* not broke, don't fix it. You can clean them really good when they are out. Also, it is easy enough to pull the fuel rail and swap injectors if something comes up later, so if you don't feel like messing with them right now, you don't have to.