1971 440 id boss numbers?

Just trying to figure out what the numbers on an ID boss on a 1971 440 mean. Engine has a casting number of 2536430-8(or-6, can't quite tell) and the vin number on block is 1C235967 so from what I can tell it is a 1971 440. The ID boss has no 440 or hp stampings but does say KMS 7700? Does anyone know what this means? Thanks for any help.

KMS 7700 is not a factory stamp. Engine was most likely rebuilt along the way and the rebuilder stamped it with a serial number of some sort.

It should be stamped G440

The VIN indicated it came out of a C body.