Engine casting 3970010...
 

I finally got around to getting the casting number off of my block, and it seems that I have just another run of the mill 350 chevy block. The code is 3970010 (69-79 or 80 350). I am trying to figure out any other information about this block, what year, what it came from, etc. I have not dropped the pan yet, so I do not know if it has 2 or 4 bolt mains. I am assuming that it is a 350 and not one of the '69 302s or 327s. I could not find a date code, but stamped onto the flat panel above the oil filter are the codes 371, 335, and 135N. The carb is a 2BBL rochester coded 17056114 and 265 5ABP which appears to come back to a 76 Monte Carlo with a 305. There is a 16 cast into the bottom of the block below the fuel pump. Also, the intake is stamped with 3887773 and GM2. The crank pulley has 458530CH stamped onto it. The entire engine is painted in chevy blue as seen in the attached picture. It was raining when I took it, and I haven’t had time to clean up under the hood. Please excuse the insane amount of blue wire loom the previous owner has scattered around the engine compartment. Thank you in advance for any more information you might have on this block.

PS...I know that the fan is not designed for a V-Belt system, I have replaced it since this photo was taken.

get the numbers and letters off the flat pad on the front of the block that is under the alt. and they will get you more info

010 is the preferred 350 block. Correct me if I'm wrong, but it has 1% tin & 2% nickel in the cast mix that helps it to wear a little better.

Its pretty much the most common small block casting number it could be a 4 bolt some are some arent it doesnt really matter 2 bolt will hold up to more power then you would want in a street motor In front of the head there should be the prefix code it will narrow it down to only a few cars in a few years If the block has been decked you wont find it or much of it

That's a high-nickle block, check to see if it's a four bolt main. Those are great blocks, I have three of them. :metal:

From what I have heard you need to pull the front cover (timing chain) off and look for a 10 or 20 in the casting. The 20 being the preferred higher % nickle alloy. My 3970010 350 block is a 10 and I'm sure it'll wear just fine as most blocks of that era were 10's.