Hello I have a 1979 4x4 Subaru wgn (4 spd). It runs well. I get about 21-23 mpg in city driving in San Diego. I use it as a daily driver and it is fun to drive. I just bought the car about 5 months ago and have already put about $2k into it to make it run better. Before I bought it, it had been sitting in someone's garage for several years. So, having said all that, I can't really answer your "longevity" question. Wish you the best!