cdrod

I'm looking at a 455 block but I don't understand the VIN derivative stamp. The stamp is 3LE 13270Y. I expected a 3XMxxxxxx format. The block casting number is 396021F with a smaller F8 casting into the rear of the block. One more unexpected detail is a large hole in the timing chain area. Can anybody shed some light on this block? Here's some pics:

joe_padavano

Or marine. That's not a GM VIN derivative stamp. Olds sold a lot of 455s for marine use in the 1970s. The hole is normal.

cdrod

Thanks Joe & Tirekicker for the quick replies. I'm much more familiar with small blocks so the hole in the front of the 455 block was not something I didn't expect. What is/was it's purpose? It appears to be above the lifter valley. Is it for oil drain back?

Rodney

joe_padavano

Oil drainback and crankcase venting as part of the PCV system.

68442

Could also be a warranty block. Anything from nothing/ Orig. VIN/ to the work order number or anything could be stamped.