A stock oil pressure gauge from a 1941-46 GMC will bolt right in a Chevy cluster. The GMC needle and face colors wont match the Chevy though. NOS gauges can be found for reasonable money from time to time. The GMC oil line fitting is different, but universal fittings can be sourced to mate the gauge. In the meantime, just drive the truck with the stock guage...it will peg out when driving down the road, but it still reads 0-30 psi accurately.
