From a 270 GMC? My recent number crunching and experimenting with Nissan Diesel pistons and sleeves in a 261 Chevy sent me down another rabbit hole. It seems that the Nissan Diesel engine has an almost identical bore size as a standard bore GMC 270, and the piston crown is thick enough to stand some energetic whittling to compensate for a stroker crankshaft. By using a smaller connecting rod bearing and doing some modifying to the GMC connecting rod, it would be possible to increase the stroke of the 270 to 4 3/8 inches, and use the Diesel pistons and sleeves, to get a total displacement of 290 cubic inches. That stroke would also be longer than the 302 GMC, for increased torque. 270s are a lot more plentiful than 302s- - - - - -and I just happen to have a couple of them to tinker with- - - - -HMMMMMMM!
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!