A 235 rod I've got handy measures 1.245" wide. That's probably the same as a 261, except for the wrist pin diameter. It looks like some adapting would need to be done on the journal to keep the BBC rod from flopping around like a catfish on the bottom of a johnboat! I made a steel spacer for each side of the 292 rod cap that attaches with flathead 4-40 screws and then gets silver soldered to the cap. Then the rod gets reconditioned to be sure it's straight and true.

Now- - - - -before we get our knuckles rapped for "thread drift", maybe we should continue our hotrodding talk somewhere else! I just picked up a 261 that didn't survive a break-in run after a pretty good rebuild for some reason, and that one's about to become a test bed for some modifications. Other than needing a crankshaft, it looks like the rest of the short block survived pretty well. Obviously, it's going to get torn down to bare bones and thoroughly inspected first.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!