There is a guy around here that claims to have a bunch of old 350 truck blocks. He said they are 4 bolt mains and wiil let them go cheap. I want to pick one up so I can start my blown 383 project. I am on a tight budget and would like to save the money instead of buying a new 350 4 bolt main for $580. What are some things to look for? Any specific casting marks? I have heard one of the numbers relates to the nickle content, but is this really true? I need your advice on this one. Any info would be greatly appreciated. Thanks.

Nickel content- the high content blocks will have a casting in the timing chain area (the timing cover would normally cover it though) that looks like this:

010
020

Do you have a dial bore gauge or at least a set of callipers? Try to find a standard bore block, don't buy something that's already .060 over.

Look for signs of oil starvation, the mains and main caps will look real ugly and end up costing you lots to fix if the engine has been starved of oil (don't ask how I know. :D )

Other than that, look at the lifter valley for visible cracks, and inspect all the important threads, make sure you don't end up with a block that needs a bunch of holes drilled and tapped or heli-coil'd.

Check core shift...notice how centered the cam bore is to the actual casting, front and rear views.

might be worth having a look to see if it is one piece or two piece crankseal as well.

71,
If you can buy a new block for $580 you will be way ahead of the game. By the time you buy the used block and have all the machine work done to make it as good as the new one, you will spend more than that.

He probably means a "remanufactured" 350??

pdq67

Stay away from any block with the small vin. pad. They have much less iron in them.

This is the block I saw for $580: http://www.paceparts.com/index.asp?PageAction=VIEWPROD&ProdID=22275 do you think that it would be a better idea just to start with a new block? I want 600hp at the wheel with a procharger, but I am just building the motor now and will add the procharger later. 8.5:1 compression probably. What kind of block should I use? I'm not on the tightest budget but I want to keep it cheap and strong if possible.

as i understand it if ya can find an old block that has 010/020 (high nickel content) stamped on the front of the block under the timing cover area and one that has little core shift, that is the way to go for the high hp build. of course that is assuming you find a block that is not already punched way oversize or any other signs of severe wear or damage.