oldbloke
Active Member
My '70 NADA 3500S runs very well on extended runs on fairly flat roads. Will cruise at 80-85 MPH if desired, but a long hill gives way to coughing/sputtering and blowing carbon(?). Power comes back going down hill...! Compression ratio is good at 135 approx, but required a little mystery oil down the plug holes. Using premium fuel and and seem to be getting 18-20+ MPG. No overheating post R&R of radiator and waterpump. Thoughts?