Bud of mine had an '81 K10 pickup bought used around '84 with high mileage for it's age (50K). Stock 305 was always a dog, began causing problems at around 110,000 miles (cam, oil consumption).
He put a rebuilt four bolt main 350 in it. TRW/RV grind cam, better pistons, etc. Someone suggested he use the aluminum intake/RQJ from the 305 and that worked out well. Ran like a bear, got fairly good fuel mileage.
That engine had well over 300K on it before it was ever replaced by the next owner, years after my bud had sold it around '94.
Only 305 that I ever owned, was in an '83 work van. Fuel pump lobe went to hell at about 95,000 miles. Installed an external "pusher" elec. pump back near the tank in the "supply" line. Anytime it got balky for fuel, hit the pump switch and off she went again. Yeah I know, shade tree but it worked.
Knew another guy that had a new Blazer w/305 that dropped a valve into a piston in less than three years.
Come ta think of it, never heard any "good" reports on any 305s?
