That should be a 4 bolt main 350
it is a 1969-1979 motor it was used in cars, trucks, and vettes
3970010 can be a 350 two or four bolt block.
Numbers on the motor of trucks and other vehicles are identification numbers for the engine block casting. These numbers identify the batch of production the engine block comes from and can be used in recalls.
1968------327 & 1969-79 ----350
chevy 350
1969-1973 chevy 307
3970010 is a 327 in the years from 1967-1969 and 350 from 1976-1979
On the drivers side of the engine in back of the cylinder head there are casting numbers and next to the casting numbers are raised letters either 5.7 or 5.0.
Chevy carte motor casting number 10066036 how much power it puting out
Find a book on casting numbers for chevys it will give you the year of the block the heads & the manifolds.
double check the numbers... i think you'll find that the first number is a 3 3970010 and it is a 350 ci
try mortec.com