What would it take to remove the air pump, diverter valve, etc. from this old gem? My drive belt goes over the idler pulley, airpump, and then to other important stuff! Are there any air pump position idler pulleys?

If you have AC, that is the only other important thing run by that belt. Lose everything except the idler pulley, which I believe is the same one as was used on the older cars which did not have an air pump. Get a belt the right length and all should work. The idler is used as the belt tensioner, but it is not a very good design. I have added a slide adjuster to it to triangulate, and it works fine.

If I just remove the air pump belt and use a shorter one, can I leave all the hardware in place? I'm wondering if I could eliminate the drag of the airpump, as well as its noise by routing the shorter belt under the airpump pulley.

Can you describe the slide adjuster? Is this similar to the screw adjusters on modern 240 belt systems?

can I leave

> all the hardware in place?

Yes, but the job is nicer if you remove everything. Is this similar to the screw

> adjusters on modern 240 belt systems?

Yes- I can't remember exactly where everything bolted to, but it will all bolt up to holes in the front of the head. All you have to do is drill and tap a hole towards the top of the idler bracket to give something to bolt the adjuster to.