"New" 1967 C-10 & Need Some Help!!

[1968robinsegg]

the block number should be located right behind the rear of the driver side cylinder head right above where your transmission bolts to the motor. it is a raised number that is cast in to the block. youll probably have to clean the area well to read it. google gm engine block numbers and youll get some websites that have the numbers listed for dicplacement and year group. hope this helps. the previous owner told me mine had a 350 but it turned out to be a 307 i figured that out this way.