Neighbor owned a 68 chevy, with a 307 two barrel in it, hauled trash for second job, he was his own company. Hauled everyday for minimum of 4 hrs a day. that engine had over 350,000 miles on it when it when it was but in my dads truck in 00 i believe. i say he hauled as in wood sides twice the size of the truck coming off of the bed, rear bumber draggin, replacing trannys every yr (auto), running through the landfill, replacing springs every two yrs and each time custom made to haul more weight, little helper springs added, pull over by the police loaded. Engine only went through one set of rings, oil pump, one set of lifters one cam, numberous valve cover gaskets, and 7 water pumps in that whole time. That engine is still going in my dads old truck, as the new owner of the truck has never had any trouble with it. It was a little low on power, but any gas engine it should be expected with those miles. Was just starting to burn a little oil when my dad sold the truck, had to have close to 400,000 miles on that engine. The owner of truck now, hauls newspapers! with it three times a week.
So far i say, once you go V8 crusier you never go back. that said with two other buddies saying the same. ALL three of mine are, one just got stripped though.