block stamp
 

went to see about a short block.owner said it was an LS 6. i looked at the pad and saw this. the casting is 361959 with a date code of A21 76 . 2 bolt main, cast crank and 3/8 rods. thats no LS 6....but any reason why they would stamp it like this ?

http://www.freeimagehosting.net/uploads/02ce2cdd33.jpg

Re: block stamp
 

It's not unusual to see an engine rebuilder stamp their coded information on a block for warranty purposes. A number of Corvette engines have surfaced with a stamp showing HD and a date. Apparently there was an engine rebuilder in Kentucky that had these initials. He'd stamp a date on the engine for warranty purposes behind his initials. It is a good, obvious place to stamp.