The casting number puts it into the correct time frame.

http://clubs.hemmings.com/clubsites/chevytalk/GMhistory/cast.html

It doesn't look like that serial number is the right one. Could the "I" be a "T"? Or maybe a "1"?

Here are some places to check.

http://clubs.hemmings.com/clubsites/chevytalk/GMhistory/1930to40motors.html

http://chevy.tocmp.com/chevyresources.htm

~#~#~#~#~
1946 Chevrolet 3600 - "Old Number Seven"

Cavalry's Here. Cavalry's a frightened guy with a rock, but it's here.