It's a fairly simple job for anyone who has the unmitigated gall to call himself a "machinist"- - - -but the guys who really qualify for that term are about as scarce as a chicken with lips! The wrist pin hole size in the piston, and possibly the crankshaft stroke would need to be altered. With the proper piston/rod combination, the stroke on a 270 can be increased by about 1/4".
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!