I agree. Those 235/261 blocks are pretty good castings, not much core shift at least in my experience. Others may have a different experience with these motors, mine is that they are good reliable castings capable of multiple rebuilds. The cranks are generally cast steel. Not a forging but not terrible either, but they are old castings. Those motors were meant for low rpm reliable use and that is how they were machined by GM. So its not uncommon to find the balance off just a little, or the throws a tad bit unequal. Other cranks are spot on. Because I am a hobby builder, I like to redo them so that they are essentially blueprinted. I have not yet had a failure so I tend to stick with what works. I agree though, that unless the crank has seized, overheated, I generally presume it can be rebuilt. In fact, I have no issues whatsoever grinding a 235.261 crank to as much as .060 over. So if a crank passes the visual inspection, off it goes for magnaflux, and if it passes, machining.
Last edited by mdonohue05; 04/20/18 11:59 AM.
