Sorry guys but I've danced around trying to figure out/verify my engine and I'm not having much luck. So here's my data if anyone has the investigative skills to decode:
1959 Chev 3100
inline six:
3764476 (found on block by starter motor)
3836848 (on top of head-drivers side)
F218J {machine flat area behind distributor) note: the number 1 could be the letter I

Thanks for the help. I'm assuming it's the original235cu engine but want to confirm

1959 Chev Napco 4x4 3100 w/235cu