I have what I believe is a replacement block 426 hemi.
This engine has been machined, built and tested on a run stand but I'm trying to determine the detail behind the actual casting numbers.

The block reads: 2468330-M

5A22

A

There is nothing stamped on the top pad.

Thanks for any help

That's a over the counter replacement Mega block, I can't try to look up the casting number (I don't have them) to see what bore size it was originally so hopefully some one else that can tell you will

Mopar block mid 90’s to early 2000’s. The first ones did not have the beefed up lifter area.
This is mine, same casting #. As far as I know these only came as non-Siamese,
replacement Hemi blocks, but have thicker main webbing than an original Hemi block.
The next version carried the same casting# and had the beefed up lifter area and was
available in Non Siamese and Siamese in either wedge or Hemi.
The Mega blocks I have, both wedge and Hemi, have the beefed lifter area.
Found this:
https://board.moparts.org/ubbthreads/ubbthreads.php/topics/2710172/nos-block-2468330-m-id.html

http://www.dodgecharger.com/forum/index.php?topic=105144.0

https://board.moparts.org/ubbthreads/ubbthreads.php/topics/2744441/mega-block-questions.html

Very good information.

Thanks to all !

Is there any information that shows the date of the Block ?

Is the 4 digit code next to the casting number some kind of date code ?

THanks

Read through those links. They mention something about the encrypted codes of the casting foundry being impossible to crack - .... except by a connecting rod

That was better than fair.