I have a 1991 F-150 with a 302 "N" code motor. It's got 160K miles on it, with the normal rear main leak, and questionable timing chain..... I am looking at swapping motors. I have a fresh (less than 7,000 miles) 1979 302 long block on the engine stand. I was gonna re-ring and bearing the long block since it's been sitting for a few years, and have been checking into compatability. The guy from the parts store is telling me that, the computer in my pick-up won't jive with a flat-tappet cam. Is this true?