[68 TT]

Looking at the way the supplemental gauges all have the same shape and construction mechanical section on the back I think it may be possible to just fit the truck oil pressure gauge with the Camaro fuel level gauge ballast resistor looking piece and change its function from oil pressure to fuel level. No drilling or re-fastening of the pieces required, just a simple face overlay or repaint to change the readings to its new purpose.

I will give this a try with some of the other spare parts I have but it will be a while before I can test it out to see if it works. I should be able to just pull out the stock large fuel level gauge and stick in the modified oil pressure gauge to see if it reads right but won't have my dash panel off any time soon.