The carb calibrated for the 261 engine will run slightly lean on a 235 because there is a bit less air volume going through the venturi. It sounds like the engine might have been running a bit rich before and leaning it out woke it up. Unless you encounter very white-burning spark plugs or other evidence of a too-lean mixture, go for it!
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!