462624 is the number on them, are they 882's? what are they if this number means anything GM8 was also found there.

nope, they are the '624' heads. They are 1.94/1.5 76cc smogger heads.

"882" is the last 3 digits of heads that end in casting number "882"
Same with all casting numbers, like 010 blocks are really 397010 blocks (High nickel)

Search the site for casting numbers, they are all listed in a database here. That's what brought me to this site in the first place. I googled casting numbers, and this came up first! Awsome info here. Anything you need as far as casting numbers, is pretty much listed.

high nickel blocks good blocks?

Yep the high nickel blocks are good because of their high resistance to bore wear.