That's right on the ragged edge of the "thinwall" block changeover- - - -not sure which way a 69 would be. 60 over is as far as I like to go, unless I'm building a short life engine. We would go through 2-3 engines a season on the dirt tracks- - - -with more clearance built into a brand new one than a 100K mile street engine. A round track engine with 1K miles on it was an antique! If you have a little extra piston skirt clearance on a 60 over engine, consider maybe putting a knurl on the piston skirts to get the clearance right, and do a hone and re-ring job. If there's less than .005" taper wear in the top 2 inches of the bore (and no score marks), you can do a re-ring without boring.

"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!