i sort of asked this question befor but relly didnt get an answer. I just wanted to know what to look for in buying a used 350 block whats the differnce in a 1 piece rear main seal and a two peice rear seal. and what should i be looking for.

 

Basically that's just the type of rear main oil seal. One piece is an o-ring design while the 2 piece is 2 semi circles. This comes into play when buying crankshafts because they are designed to work with one or the other.

I would be looking for a regular 4 inch bore block. I wouldn't even want to mess around with one that's been bored out already. That way if you plan on getting it bored there won't be any hidden surprises. Same with having a OEM surface not an already machine deck'd one. You'll definitely want to figure all this stuff out before hand. It would really suck to find out down the road you can't run the pistons you want because of compression or bore.

No rust on the inside or on any gasket surfaces, no stripped threads, no broken bolts in any thread'd holes is always good too. Really should be fairly picky on stuff because you'll more than likely be dropping acouple hundred bucks into machining the block and it would be really bad to have a bad core to start. (Which happen'd to me once.)

Passenger side oil dip sticks are nice too, I'm told you have to becareful with driverside ones due to some header designs. Mine clear'd my hooker long tubes fine. Rest is just personal prefrence really. More than likely you'll be looking for a roller block. Having pre-tapped plug holes for the oil gallery and sides is usually a plus IMO.

 

thanks