How I know so much about these engines is because I somewhat specialize in modifying Picco engines..... Every single motor I modify is timed, both sleeve and crank.. every motor I modify has both crank and sleeve timing altered.... So over the course of the last year I have worked on several dozen of these engines....Picco will change timing and crank bore, but those variences will be in all 3 variations of the Picco ( Drake,JPX,Picco) all the offroad .21's share the same crank timings, same opening, same closing.... You will see a oddball crank with a extra few degrees every nowand then...Some JPX mills have a 9.8 mm bore, others a 9.9 mm bore...some are harcoated all the way thru the crank...others are bare metal dowm the bore......... older .21's had transfer ports opening earlier then boost, lately Picco has been opening boost a little earlier... Month to month I see a swing int he way Picco times and builds then engines... Adam from AB mods also hand times every engine and has also notices when Picco updates the lineup.