123cu swap to 135?

Hugh,
I would like to see that earlier thread when you recall it. There are two different flavors of C135 crankshafts (just based on journal diameters) and neither of them will fit in a C123 block without extensive machining. The later of the C135 cranks (poss both of them?) even have the wrong width on the number 1 & 3 mains. Tractor pullers might try it, but they have different expectations. I wouldn't recommend it for normal use as being cost prohibitive and you loose the hardened surfaces from the crank.
Stan(VA).

I do remember he was advised of three options, with a couple of variations; bore a C-123 block and install a 404 crank, find a 404 engine, find a 330 or 340 engine and either change the crank or modify the crank and flywheel. Most folks seemed to think if he went the 330 or 340 engine route, finding a 404 crank would be easier than modification of the existing crank and flywheel. I'm not sure finding a 404 crank would be easy, that version was not a high production numbers engine.

My only involvment in this discussion was going through some specs I had at hand, re the idea boring the C-123 engine and finding a 404 crank. We did a complete comparison on everything bore, stroke, valve settings, cam, etc., etc.

This will be in the archives, not sure of title, don't remember his name or handle off hand. It will come to me in the next 48 hours. There will be 2 or 3 threads on this subject. I do know he was getting the strongest advice to bore the C-123 engine and be satisfied with larger bore, and forget about the longer stroke, it wasn't going to change power greatly. My thoughts at the time was find a 404 engine, as he would probably need to buy a complete engine to find a good 404 crank anyhow.

Had the C-135 come from a 404, it would bolt right up as both it and 240 have transmission driven pto.