The plugs in a 235 are at such an angle that a regular "positive stop" tool will not touch the piston. When the "UC" mark on a 235 flywheel aligns with the pointer in the window above the starter both #1 and #6 pistons will be at TDC. The ignition timing BB will be close enough to top center to check for spark plug interference.
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!