Sorry, but I'm coming into this discussion at a late stage... When talking about a particular block and which Make and model automobile it was originally installed in the first two things you need to know are the Block Casting Number (which you have) and the Block Casting Date (which you also have). These facts will tell you the year of the vehicle the Block originally came in (and in some cases will rule out specific models). The partial or "Confidential" Vehicle Identification Number that is stamped on the block has a model year indicator which should correspond to the Casting Date Code information.
NOTE: The modified Block Casting Number of 979991(5) was only used on the Ram Air IV engines. This is where the Pontiac Engine Assembly Plant took a select 9799914 block and modified it for use as a Ram Air IV Block by grinding off the "4" and hand stamping a "5" in its place. Please note that counterfeiters have been know to grind off the "4" in an effort to fake a Ram Air IV Block. Pontiac Engine Blocks also have a "Use Code" stamped on them. The factory Ram Air IV Blocks have a "Use Code" of either "WW (for a 4 Speed Manual Transmission)" or a "XP (for a TH400 Transmission)." However, I understand that these Ram Air IV "Use Codes" can be also be faked by re-stamping. Your "Use Code" of "WS (Ram Air III 400 with an Automatic)" could indicate that at some point someone other than factory personnel messed with your Block Casting Number.
Your Block Casting Date (H269) should indicate a very early 1970 Model Year Automobile (with an Assembly Date for the Automobile of mid September, 1969 -- during the 1970 Model Year).
So you have a 1970 model year Ram Air III engine (originally) backed up by a TH400 Transmission.
In order to extrapolate a full Vehicle Identification Number from just the block numbers you'll need to make a guess at what model Pontiac the engine originally came in. Because the Ram Air III was available on only the GTO or the Firebird Trans Am you only have those two possible Vehicle identification Number prefixs to select from. Therefore, the full Vehicle Identification Number for your engine would be either 242370X123456 (for a GTO) or 22887X123456 (for a Trans Am). Furthermore, since the Trans Ams were built at only the Norwood (Plant Code "N") or Van Nuys (Plant Code "L") Final Assembly Plants you can cut down your guessing: If your Partial VIN shows an "N" or a "L" as the seventh digit then the block obviously came out of a Trans Am. If the Partial VIN shows any other code letter (A, B, G, P, R, Z) that would make it a GTO.
I didn't see a Partial VIN listed in your prior posts... That data would be interesting: Do you care to share it with us?
Last edited by Red1970GTO; 01-01-2014 at 01:12 PM.
Reason: Spelling-- my bad!