help with block id
 

I found a block in my dads garage. I need to find out what it is. I'm pretty sure its a 350. I'd also like to know what year. This is the number 3970010
Thanks!

There is a date code found on the bell housing flange, usually at the rear of the driver's-side head location. There will be the appearance of two screw heads, one on either end of the date code. The typical date format is "alpha, numeric, numeric," or in the case of a block that happened to be cast today H808. There are variations but if you find the code, post it and we'll see if we can figure it out. If the block is a four-bolt, it was a 350. If it is a two-bolt main, it could be a 350 or it could also have been a 327 if it had been equipped with a 3.25" stroke crankshaft.

In the area covered by the timing cover there are probably other cast digits like "010" or "020" or both. Note those as well.

On the block pad that would protrude in front of the passenger side head there may be a series of numbers and letters that were stamped into the iron. If those are legible it will be possible to tell even more about the history of this block.

An 010 block just means it's a 4" bore block. That casting was used for 302, 327 and 350 engines. If it doesn't have a crankshaft, then it's a good block to build into a 350. If you want to know exactly what it was from, get the numbers that are stamped into the pad in front of the passenger side head.

Thanks, It's a 350.. for now. Its going to be a 383 stroker soon. Again, thanks for the help.