I'd plan on replacing the entire exhaust system with the larger pipe size and a muffler capable of flowing the extra volume of gas the 292 will produce. If you want a quiet exhaust, the muffler for a mid-1970s Cadillac has 2 1/2" inlet and outlet pipes and it can handle up to a 500 cubic inch engine without excessive noise or back pressure.
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!