As I mentioned above there is 14GM cast above the oil filter and the H18 is in fact H1 B. Still unsure how to decode that for the casting date, if I have got the right numbers.
Hi Wayne -
The H 1 B is not
the block casting date. On your small block the date that the block was made is cast into the rear of the block, next to where the bellhousing bolts up, on the passenger's
** side. In my block casting date photo below, L 19 7 decodes to December 19, 1967. If you can get the block casting date it will help to solve your mystery. Hope this helps!
** Kurt, the location of the engine block casting date is wrong on the CRG Drivetrain Decoding page. It says the casting date is on the driver's
"The date that the block was made is cast into the rear of the block, next to where the bellhousing bolts up, on the driver's
side. Some big blocks will have the cast date next to the engine mounts, near the freeze plugs."