I'm still confused, which I6 is this?

[pritch]

I've asked this before, but the answer don't seem to jive with what I've found as I tear down the motor. The casting # is: S48675 and the stamped # is: FO204CJL. The answer I got before was '75 250 1BBL, 105 HP. My book says that the only real difference between the 230 and the 250 is stroke. It says the 230 is 3.250" and the 250 is like 3.580 or something. The book ain't in front of me so I'm guessing on the 250, but it was just over 3 and a half inches. When I measured the stroke on my motor, it was 3.250. It's easy to tell the diff. between 3 and a quarter and 3 and a half. So now I'm really confused because, again according to my book, they didn't make 230's in '75.

It has a broken piston. Looks like a ring came apart and banged around for awile. I think the PO rebuilt this motor (poorly) and broke a ring putting it together or not leaving enough ring gap. I think when the ring broke it took out the head because 1) the head shows no damage what so ever, while the top of the piston is all banged up, and 2) the head is a diff. shade of orange, so it wasn't painted at the same time at least. And 3) about 1/3 of the top ring was gone and 2/3 of the second ring was gone, along with about a nickel-sized chunk of piston from where the rings are. None of this was present inside the motor. I think the PO pulled the head and cleaned out the junk from on top of the piston and not seeing the missing rings or the side of the piston, figured he got away lucky with a new head. Lucky, too, that there don't seem to be any damage at all to the cyl. wall. I just need to come up with a piston. Are they the same for the 250 as the 230?