I just ordered a set of Ford 223 pistons, which are 3 5/8" bore and approximately 1/4" lower compression height than a 235 piston. With a stock length stovebolt connecting rod and a 5/16" stroke increase, the pistons should get very close to the correct deck height to work well. The Ford wrist pin is only a few thousandths larger than the stovebolt pin- - - -it would be easy to ream or hone the stock rod to the proper diameter, or do a little more tinkering and use a long aftermarket I beam rod for a big block V8. A 260+ cubic inch displacement using the readily available 235 block would avoid having to search for those scarce and expensive 261s!
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!