help me figure out this engine code please

[SS Shaun]

can someone help me figure out the code on my motor for me i am reading a link on it but i am not sure if its correct. here is what is stamped on my motor
C6b173362
so if i am reading this right it right the C=March the 6- the 6th day but what is the B? so if this is correct the ref is correct the motor was built in 71
so i have March 6 1971?
but the stamping on the back of the motor reads
361959

and then the heads are
336781

can someone help me figure out what these are. and are they any good?c