engine number help

[philB]

need some help on what I have for a sbc engine, have a '69 C10 ss/swb and had a good running small block, owner said he did not know what size it is, the person he bought it from told him it was a reman engine but he is long gone, but looking for info on the motor block showes nothing as to size, block stamped on front right side in front of the head 46199C, if anyone can help id it as to size etc. would be helpful as we go thru making it better than before, dont want to replace the motor, runs too good, thanks.