Warning: my odometer rolled 100,000 miles on my 1971 Nova and my oil pressure gauge told me a story
Last Saturday I hit 100,000 miles on my 1971 Nova, which sounds small until you figure that engine has been rebuilt once and the odometer got reset back in 1998. I checked the oil pressure right after the rollover and it was sitting at 18 psi warm at idle, which is about 6 psi lower than it was two years ago. That drop told me my bearings are starting to go, so I swapped in a mechanical gauge to confirm it was not just an old sending unit lying to me. Pulled the valve covers and found sludge in the rear corners, so the oil changes I skipped last winter did more damage than I want to admit. I am now running 20W-50 with a zinc additive and watching that needle like a hawk. How many miles do you guys go between oil changes on a rebuilt small block, and does anyone else trust a mechanical gauge over the dash one?