3406b info?

Hey fellas, I’m new to the forum scene hopefully I’m posting in the right place, I just recently bought a project truck it’s an 85 Pete 359 had a motor swap originally had a 3406b but replaced with a different serial number but still a 3406b in it right now. I have a couple questions I tried asking my Peterbilt dealer he couldn’t come up with anything but my serial number is 7FB94590 I wanna know is this a 425 cat? Also the previous owner said it’s a B engine with C internals could you tell me what that means? Any info on this serial number would be very helpful, also have 1 more question I have threaded slot underneath my oil cooler could you tell me what goes on it has 2 prongs some kinda inlet pipe or hose should be on it I’m assuming, thanks in advance

 

Oh ok that makes sense about the bearings and crank but this might sound dumb but I’m new to the mechanical motors, what’s air to air and how can I distinguish whether or not if I have it?

 

Absolutely my freind I’m always respectful and always willing to learn how do I get in contact with him?

 

Interesting, I have only 1 radiator nothing in front of it so guessing that means no air to air, but only thing I can think of is the oil cooler which would be the slab your talking about nothing else rings a bell so confused about that now

 

Yea sorry brother I’m no good with these internet sites I just had my daughter explain to me that I could’ve clicked your tag lol I messaged him and I appreciate your help