38337004
1955-1957 235
http://www.1954advance-design.com/Stovebolt-engine/casting-numbers.html

F - Flint, Michigan engine plane
12 = December
12 = 12th
B = Powerglide equipped
http://chevy.oldcarmanualproject.com/chevyresto/57011.htm

If my decoding is correct, you have hydraulic lifters. This is no problem, but you will have to adjust them appropriately.