Danubus

I purchased a set of pull off 243s from a member in the classifieds. I was under the impression that they were stock heads. When I got them they had dual valve springs installed. I am sending these out to AI to get ported. I just want to make sure that these were not previously worked on. I don't see any evidence of previous porting, but i found numbers on the exhaust manifold side as well7 as just below the valve cover seat. I am curious to know if these are just some kind of manufacturing id tags or if they are some sort of shop markings to id previous work. Sorry if this is a stupid question, but any help would be appreciated.

LilJayV10

iTrader: (39)

Those are stock GM markings.

Danubus

Thanks Jay. I figured as much. First time I really inspected a set of heads up close.