What block is this?

I think the 3830830-400 block casting is a rare Road Runner only block. Had to get the 4bbl motor thought.

:rofl:

Just a joke, but I do have a block with that casting number that (per the seller) came out of a ‘75 RR. VIN stamped on the block starts with 5B so seems reasonable, and I saw a 75 RR in his driveway so I think it is legit.

No idea if it is the “big” cam, dual exhaust E-68 motor though, but it does have the 4bbl intake on it. I would have guessed the E-68 motor would have a forged crank (this one is cast), but just a guess on my part.