well I looked around and I can't find out much about my flat 8.
On the block is GCC5O,on the heads are, right C8CM-C,left ICM.
It has 24 bolts in the heads with the thirmastat at the front,
It had nerrow pullys when I got it and a carter carb that looks like around 1950's.
any help would be apperaterd
(can't spell but can pull a wrench LOL)
Check out my answer to Huggy Bear just below - you have basically the same thing, but the ICM would make me think 1951. Only way to tell for sure is the right passenger side intake flat on the block - look for the alpha-numeric series of stampings. Post what you find and I might be able to interpret. Out of curiosity, are the heads aluminum? Probably were made in Canada. Block casting numbers haven't been categorized by anyone - only random numbers at this point.
You won't know if you have a 3 3/4" or 4" crank without pulling the pan off. I take it you have a 4 bolt pattern on the carb base - which would be a Merc intake manifold.