I have a 350 from a 1981 pickup. I looked at the casting numbers on the front right side of the engine and there is the regular "V0504UHW" number but there is a second stamp I believe reads "CBZ140689".

Any ideas? I took the pan off and I've never seen a used engine so clean. It honestly looks brand new. Could the second stamp numbers be from a engine builder/rebuilder? That's my best guess. Anyone else?

 

Could well be, or someone was very good about doing oil changes. That lower end looks spotless like new. I' ve seen that with people who take the time to use great oil and change it often, but it might be a rebuild since the plate has the two numbers which are not stamped the same way. Back n 1981 we used to drop the oil every 3000 miles or less, since synthetics were not as popular as they are now..

 

No doubt. I was awe struck when I saw how clean it was. Even the cam looks like new with no signs of wear. I'm going to gamble that it is indeed a rebuild. I'm sure I'll learn more when I take the heads off tonight.

 

most times when blocks are milled down those numbers get wiped and new numbers get stamped. but the hand punched numbers resemble a partial vin
the engine code as you may know is
flint may 4th 1981 350
but the engine code is the last 9 digits of the vin. the C would be the "check number" B is for the year (1981) and z would be the plant then the last numbers are the sequence numbers

so although the insides of the engine may have been rebuilt those numbers are original

 

Great info! Makes sense.

Thanks again