I'm going to run mechanical oil pressure and electric temperature guages on my 71 Challenger along with the factory guages, at least until I can determine if the factory guages work and are accurate.

So where is a good place to run my plastic oil pressure line and my electric temperature guage wire through the firewall without drilling any new holes?

Thanks.

Hello! First, don't use the plastic junk that comes with an aftermarket gauge kit. Go to NAPA or someplace like that and buy the copper tube kit for the oil pressure gauge. Comes cut to fit. Much safer! I ran mine thru the speedo grommet. Jeff