Options for a tach where fuel gauge should go?

[Gmc.guy]

I know the tach should be in the center smaller gauge spot, but my 69 is set up for propane and it's not set up for dual fuel. Tired of looking at a past-full gauge, the fuel gauge is on the top of the tank in the bed of the truck, visible out the back window. It does not have a tach now, Just looking for ideas. I was thinking trying to adapt one from a 73-87 and getting vinyl decals done for original style lettering
Also wanted to say thanks to all the info I got off this site in the past and great respect to all the projects and help you guys give to all.