I go big. O2 milivolts read 813 at toward the top of third, 0.0 KR (until carnage)... Like I said, unknown bottom end. I've been racing motorcycles all my life- pistons looked cast, hyper at best. Why not run cast?! You can get all of ten hours in a small bore 2 stroke before the skirt cracks...
I've been there before when I got so good at swapping out 455's in my 68 GS I could literally pull the bad one out and put a running engine in the car in about three hours [by myself] and be on the road again.
I went through three engines in one month one time. In fairness they were takeouts not rebuilds.
Stride comes with age I guess. Honestly, its devastating- you can laugh or cry... It's not worth anything not running. I just wanna do it right, and know what I have...
Does a sleeved block lose strength over a non sleeved or is it not the weakest part of the block to be worried about ? I have a 109 block that could use a sleeve.