[LPI]

Originally Posted by LMSRACER

For those that don't know, He's talking about the 455 Block when he says "9799 thru 485".

Also, for those that don't know, the Pontiac Dowels are 0.3095" and NOT 0.3125" (5/16").

I am referring to the factory Pontiac "block Cylinder" drawing and OEM specifications for the design of block 9799914, A 400 block. The subsequent designs and revisions which happens to be the base design drawing for a base block (which happens to be the 400 CID) and subsequent changes including the following blocks 9799915, 9799916, 97999140, 9799141, 481836, 490132, 485212.

Each block casting number received an additional drawing outlining details for that particular block. This print 9799914 is the basis for the castings and design intent for the 1970 production 400 blocks and 455 blocks. Hence the reason for reference to the two casting prefixes.

Here is a 1968 400 casting 9790071 fitted with 5/16" dowel pins and piloted washers in the main caps to be used with ARP main studs.