engine I.D. help

[steve53]

Hey guys,

I got my hands on a straight six and need some help finding out what it is exactly. I got it all torn apart now and am cleaning it up as well as checking my area for places to get the head worked on. Here are all the numbers off the block. If you look at the side of it, here are the numbers starting from flywheel end to fan end.

this first set is raised letters: CON2 1235 3877178C GMx 31 and stamped next to the distrib: FI228TF

I checked http://chevy.oldcarmanualproject.com/models/engine.htm and it doesn't seem to really match up. The friend that I got it from thinks it is from a 55-59. Thanks in advance!

-Steve