Welcome to CHR Twolane -

I think you’ve got one too many zeros in your number. My guess is that you have a 3970010. This casting was used for 1968 327 and 1969-79 350 (2 and 4 bolt). Four bolts were used in trucks, Camaros, and ‘vettes during those years with HP up to 370. Good builder – but not a roller.

The numbers on the front pad (passenger side – lip on the front of the block example would be "V0722TXD") are the key if you want the specific application these engines were originally used in. Get those numbers and we can give you some more info.

Regards,
Glenn