I've never built a piston guided engine but don't see how this would help. My problem is on the main thrust, not rod side clearance. Crank still floats and needs end play limited. Course it is possible I don't completely understand all there is in the piston guided setup. Still couldn't get a 6.1 type crank in. Am I missing something? I'm don't even see the benefit of piston guided in any engine. As I understand it the small end of the rod is floated but it has very little side to side clearance so big end width of the rod is not as important because the rod is basically located by the side play at the piston, not the crank. Am I right? Like I said I have never messed with this. Never even seen it.

As for the cranks I have they have the same dimension rear seal and flywheel mount flange. 6 bolt. They are also setup for the 4 screw tone ring.
Only difference I can see other than 48lb vs around 63lb is the rod throws are honda diam. and mains are LS diam. and #3 is LS width on the thrust. Narrow.