3835497 is a Block Casting Code for a 216 - 1948-1951

Engine Serial Number: HBA943391 or HBA 94339I (the "I" stamp was used "interchangeably"/mistakenly for the "1" stamp at the factory)

H = 1950 Flint, Michigan engine plant
B = 3100
A = regular transmission (3 speed) and clutch
943391-1000 = 942,391st engine out of that plant that year.

http://www.1954advance-design.com/chev-specs/1950-Chevrolet-t-ser.pdf