I cant figure this one, got a 340 and im positive the date on the pass, side is 1-15-71. But when i checked the numbers above pan and they began 2B2 which is 72, any ideas on this one ??

thats fine, the plants switched to the 72 model year in august of 71 i think???

71 block in a 72 what's so odd about that?

Looks like the block was cast on 15 january 71 but wasn't installed until the 72 model year was in production .
Usually this stuff is made a year ahead of time. That 72 demon was built around august or earlier of 71.

is the "B" stand for cuda ?

B = Hamtramck Assembly plant

I think Hamtramck did mostly A&E bodys

how am i able to determine what car this came out of ? also (2B23981) is what i read off the rail, isnt a few numbers missing ? or is that all that of the vin that gets stamped into the rail

Read the front of the block, drivers side right where the head meets the block, it will give you way more info.

this is what i can make out from front HM 340R 37300(0)8 the number in () is half gone

low compression ? it does have steel crank thanks

3730 is the build date October 14, 1972 which is in the '73 model year, strange to be found stamped with a '72 VIN.