69 350 250 or 300Hp motor?

[veener88]

For christmas we got some chevy books to help restore out 54 3600 and 69 c10. On the C10 we came across in one of the books that there was a limited amount a little over 28K of C10 that came with 350 that were 300HP instead of the 250. But my other books only shows 255 HP motors came in the truck. What the books did help me with is that I did not know there was a option sticker glove box ( I am just starting to restore this truck still learning). So I found that engine code option was 4LS9AA, with a 3.73 rear end a turbo trans. I am just wondering how can I tell what 350 is under the hood? Right now the engine is to coved in filth to get a good look at the stamp on the block and I can not even find the code for what one is what.

Thanks for any help on this.