Looking at Treats pistons I noticed this.
To the center of wrist pin and total length not including crown.
There were two more at 28-53 but the 53 was listed as total length including crown.
It looks to me like the piston height from the center of the wrist pin varies from 27mm to 28mm. Stepping up .5mm, .8mm, and 1mm.
What does this up to 1mm variation have on timing and compression?