Help with sbc date code

[AZ59apacheguy]

So my buddy bought a '56 3/4 ton truck. The truck has factory V8 mounts and we are having a hard time figuring out the date code that's stamped on the front passenger side of the block. The number there is F226M. So far I have deciphered June 2nd? But I'm not sure if the 6 at the end is '56 or '66. I know the block code is on the drivers rear, but it's so caked back there we cant see it.
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[mr48chev]

A quick look under it on the side of the block will tell if it is actually a 56 block or a later block as the 56 block won't have the three bolt holes for the side motor mounts like the 58 and newer blocks do.

I looked on Ebay and found this http://www.ebay.com/itm/1956-Chevrol...item23269b746b
You can see there are no motormount holes on the sides of the block.


You can see the raised pads for the side mounts with the holes in them in one of the photos on this link. bottom row next to last photo.
http://www.ebay.com/itm/1964-CHEVY-C...2b1ec7&vxp=mtr

[AZ59apacheguy]

Thanks for the reply. I did not notice if those side mounting holes were there or not. I did notice that the valve covers had staggered bolt holes, that should narrow it down a little right?

[mr48chev]

Yes the staggered holes mean that the heads were the earlier heads.

[AZ59apacheguy]

Originally Posted by mr48chev

Yes the staggered holes mean that the heads were the earlier heads.

Well at least I was in the right direction with that. I'll have my buddy look to see if these are side motor mounts tomorrow. Thanks again

[AZ59apacheguy]

You know come to think about it, the block had an oil canister filter, so that rules out a 265. So with that being said, does the date code say it's a '66 block??

[OrrieG]

I could not find info on that engine number, might be a replacement block. I did find this thread that has lots of "how to" ID information.

http://67-72chevytrucks.com/vboard/s...d.php?t=386581

[craig32]

You're not even close. F is for a Flint engine, 226 is Feb 26th, and M is the application - the only M listed is for a 1958 truck. Staggered holes in the valve covers changed in mid 1959, so they are correct. The Canister oil filter came out in 1956 on the 265, so it is correct also. There are adaptors to put a spin on oil filter on the older engines, so it can be updated if desired.

[AZ59apacheguy]

Originally Posted by craig32

You're not even close. F is for a Flint engine, 226 is Feb 26th, and M is the application - the only M listed is for a 1958 truck. Staggered holes in the valve covers changed in mid 1959, so they are correct. The Canister oil filter came out in 1956 on the 265, so it is correct also. There are adaptors to put a spin on oil filter on the older engines, so it can be updated if desired.

Oooooops. Thanks for the info. See, that's what's great about websites like this, you get the correct info instead of trying and interpret things on your own. Thanks again

[craig32]

You would have been right if that were the casting number, as they have a letter for the month, and numbers for day and year - but no other letter. And it is a 283, btw, 160 HP. Flint and Tonawanda engines are pretty much territorial, the only Flint model I have came from Nebraska.
You didn't say, does the engine run??

[AZ59apacheguy]

Hi. Yes it runs and runs great I might add. I had a chance to drive it and there was plenty of power and sounded great. Makes me REALLY excited to install the rebuilt 283 I'm working on in my '59 1/2 ton.