Need P# for 8-3/4 vent screw

I always got mine in the junk yard, and tried not to lose them.

I believe the last one I got was off a 9.25.

The late model stuff is a hollow bolt with a nipple, and they run a hose to a small filter with a clip on a cross member.

sweet, so its the same size on the modern stuff as it is on the 8-3/4...may sound goofy, but what did 9-1/4's come in and what years so i know where to look