whith proper tuning a 305 will do very well it is a more eficiant engine. if you look a stock factory specs inch for inch the 305 is very a respectableperformer. I my self run one in my 82 Seirra long bed and when hualing 1500lbs of doors it moves right along. We did a honest everyday situation test at our shop two weeks ago. We took the 3/4 ton chevy with a fuel injected 350 and hooked it up to our door trailer wich was loaded an ran up the highway then hooked up the trailer to my truck and ran it up the highway which one pulled better mine did but not buy much what made us decide to dedicate mine to the job better milage. we are a lumber yard with door shop and windows and our trucks get a lot of towing and hauling miles the 305 has yet to letus down.