First off practically everything built from 71 up was built for unleaded gas even though leaded was still available. It seems like the older engines don,t give any problem if not driven hard. I ,ve had a bunch of them & never added anything & never had a problem. A fleet of trucks I used to work on switched to propane, in spite of my advice not too. The Fords wallerd out valve seats in a few miles but the chevy,s seemed to do OK.
