That block casting code (3764476) has been reported to be used a some car & truck 235 engines from 1956-1962.
When used on a car it had hydraulic lifters (all truck 235s came with mechanical lifters).

Casting date (block): K 20 8
K = month = 11 = November
20 = day = 20th
8 = year = 1958 (a late 1958 engine could have been used in an early 1959 truck)

Engine "ID": F1121J
F = Flint, Michigan assembly plant
11 = month = November
21 = day = 21st
J = regular production 3100-3800

What is your Vehicle Serial Number (on metal plate on driver's side body hinge pillar)?