That gauge is where the PRND21 display was for the slushbox. It's a vacuum gauge from Harbor Freight. I see now that they've discontinued it and replaced it with a boost/vacuum gauge...lame.
Anyway it was a perfect fit for that spot, although I haven't put in the effort to devise a mount to make it stable and well-aligned so it's usually a bit cockeyed.
Unfortunately the faux woodgrain was rubbed off by a larger rubber-backed vacuum gauge I had resting on top of the steering column before.
I also have one of these, had it for a year but haven't done anything with it yet:
It would take the place of my one huge fuel gauge. It's just the guts and face, no lens or can, so I want to get a gauge from a junkyard to hack instead of hacking my own...but they're surprisingly tough to find.
Want a tach and an oil pressure gauge. No idea where I can mount them. Would love this series, would love the entire set:
They're ridiculously expensive but they look great and the tach is available in 5000 and 7000 RPM versions as well as the more common 8000-10000 ones. Not sure how many RPM this engine is good for but I don't think I've ever hit 5000.