Check this link:

http://www.ebay.com/itm/1960-1962-Chevrolet-C10-truck-manual-transmission-235-engine-flywheel-ring-gear-/291579586582?fits=Make%3AChevrolet&hash=item43e37f6816:g:p2cAAOSw37tWBEHs&vxp=mtr

Every 235/261 flywheel I've looked at on ebay has three dowel pin holes- - - -chances are somebody has installed the flywheel in the wrong position.
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!