here is what i have, cast #3970010 date code h-21-0 #'s stanped on front of block. behind alt are VO8252 then the stamp is bunched together but looks like 2DI i cant find this # anywhere. what could it mean also next to this # is c-10-7 head casting is 3973487(350 75cc)same date code h-21-0 what could those numbers on front be and is this a decent motor seems it was built 5 months after car thanks. btw head casting says used on 71-72 350lt1(did not see an x)starting to think if i slap a 4bbl on it(has2bbl)and non-highway rear car may go somewhere!but bring me back down to earth if you may. was told car has 307 help. graemlins/beers.gif

The block casting number was used on 302'2, 327's and 350's. Given the dates I'd say it is a 350 since the 302's and 327's made using that block list as 1969 only.

The heads also list a 350 heads, some could have been used on a 71-72 LT1. A smog head for sure given the date and the 75 cc size, but pretty decent heads nonetheless.

I've no idea what the other codes may indicate.

Thanks. 350 is much better than 307