ok, this is some info i got from another board, any of this sound right ?

"If it's a 71 core engine then external balance is simply meaningless to you because that started in 1979 and does not apply to your engine at all."

here is the info i have on parts i can see, i cant actually get a true date, only casting numbers,,

Block D1VE A2B
Heads D3VE A2A
Intake D6VE 9425 A3A
Water Pump D2VE BA