The 1947 - Present Chevrolet & GMC Truck Message Board Network

I bought new spark plugs the other day for my 64 long step. When I pulled one out it was different than the ones that I bought. According to the parts store site, the 230 in a ‘64 should use a NGK 2636 GR4 or equivalent. This plug has a 13/16 hex and with a gasket seal. The plugs that are in it now are AC 46 TS. This plug has a 5/8 hex and a taper seal. The machined area in the head is too small for the 13/16 plug. So I spent the better part of today doing research on my engine. I thought I had a 230. Now I believe it is a 250. I have looked through this site, Stovebolt, Inliners and many others. I was able to find a match for my block casting numbers on the site http://www.enginepartswarehouse.com/...ERALMOTORS.PDF
They list the engine as a ’73- ‘79 250ci. My block has a 3 hole starter mounting that bolts on from the end not the bottom. The top bolt threads into the housing. The starter looks like the one from AZ for a 230. This is confusing. Can the 250 use this style starter too? From the head casting #, http://www.inliners.org/tech/heads/headindex.htm shows it to be a ’73- ’79, 250ci., 72.76cc or from a “75-85, 250ci., 72.76cc

Casting numbers
Pass. Side in front of the starter: 348675
GM
Above starter: CON 2 F44
Head above the dist between 1st and 2nd spark plug: 2084F58
Head: top under cover near the clock:
GM B148 331184 clock
45
Stamped numbers (are these referred to as the engine serial)?
Pad to the rear the dist: F060b TDF 2nd row: C47176345

Am I looking at the right numbers? If you have any info please let me know.