my 1979 sw truck was built with a 305, got over 225000 miles on it before I went with a 350, never had to go inside that engine for any repairs, the engine still ran fine but struggled going over the coast range pulling a 7X16 enclosed trailer with 3 quads in it, the 305 has been sitting in the garage for 5 or 6 years, just can't bring myself to give it to the scrap man, Steve