I opened my '84 B-2000 to adjust the idle speed up a bit. To my amazement the top portion of the carburetor was floating around when the air cleaner housing was unscrewed. The gasket was broken and the top of the 'bowl' was missing all three mounting screws(?). Where can I find a resource that will tell me what size screws or bolts fit into the carburetor to replace the missing parts. I put the air cleaner back on, adjusted the placement as best as I could and drove away! Someone suggested the Mazda dealer but it is kinda old and I haven't tried them yet anyway. It's a two barrel I believe. Thanks

Most likely the threads are stripped now anyway. Put whatever you can get in the holes.

Try matric screws of different sizes to se if the threads are OK; if not, tap to the next largest size (even if that's SAE, to remove as little metal as possible).

For damaged threads, get a tap of the correct metric size and clean the threads. You may restore the damaged ones to the point that you can reuse the original bolts in them.