I managed to find two Goodwrench 292 engines for my 1951 Chevy 3800 pickup; my rationale being that I should be able to make one good one out of the two. Both need to be rebuilt. My question regards identification. Both are Mexican-built, block castings 93411147 and head castings 93413990. Both show GM 4.8L G on the pad behind the starter, with no casting date codes that correspond with any format I have been able to find. Above the GM 4.8L G casting is 151, with 96 further to the right on one, and 261 and 98 further to the right on the other. The stamped I.D. on the 151 block (on the distributor boss) is M07056SV, which to me indicates a build date of July 5, 1996. The other is stamped 2M09239SV, built Sept 23, 1999. Both heads have casting "96" and "98" respectively. Given that the 292 was discontinued in about 1989 in vehicles, but it is my understanding that the Goodwrench replacement engines were still available until 2000 or 2001, is my theory that these blocks were cast in May 31,1996 (Julian date 96151) and Sept 18,1998 (Julian date 98261) at all feasible? The build dates seem to be possible if we accept the casting dates as possible. Any former dealers/parts gurus out there that may have reliable input into this question? Also, any good info on the "SV" suffix on both engines? Does it just designate a Goodwrench replacement engine? Sorry for the extended rant, but reliable info on these engines, particularly on the later "M" versions, seems to be very scarce on the net. Thanks for reading all this, and thanks for any and all responses. I have pictures if anyone wants further verification, not sure how to post here, PM me at packhousemike@gmail.com

You have done a good job figuring out what vintage they are and you have 2 good candidates. It really does not make anymore difference to identify more as they are simply core engines to rebuild.

Your frustration has been voiced here many times in the past, and it has been determined that the Mexican cast blocks and heads have no database to decipher them like the US cast parts have. As Tom said, the info you seek is largely irrelevant and you basically have 2 desirable cores to start with.

The Mex blocks have been known to be thicker then the USA. Many Hard core racers would go after those Mex Blocks over the USA blocks.

Thanks for your responses, gentlemen. I know that the exact build dates are moot points, just my picky nature, was basically looking at the relative age of everything, and it seems it paid off, in that both blocks seem to be stock bore, so although they both need bored, there should be plenty of material to work with. Tom, I'll be calling you in the next couple weeks to discuss my build. Need to finish a couple of Harleys to help finance my dreams.