I have a 77 cj7 with a 401 out of a 77 Wagoneer. Recently I had new gears installed and it sounds like the engine is going to come apart when it’s running at 2500 RPM’s. The gears I had in for the last 2 years were 2.73 and I just had 4.88 put in. If I were to run 2500 RPM’s with the old 2.73 gears I would be doing 90 MPH. So my real question is what is a safe range to run on the highway or even on the streets with a stock 1977 401?
Thanks for any help you can provide.
Chris