good evening to all, i just purchased a old junker of a 350 i was told and so far all the markings i can find is on the driver side of the block with HECHO EN MEXICO and the numbers 3978010 under it any ideas what it may be and how old. haven't dug the grease and dirt off all of it yet. Didn't see anything on the passenger side, it needs a total makeover badly. A great project engine for my son and i if it's worth it. thank for all the info that you can send my way!