but the yam rods still 10 mm too long,std early 90's XR400 piston has lower deck height than XL's piston,thats why i use wiseco XR ,it's higher comp in XR,but normal in XL use,not sure what the deck height actually is,but it might help, are the pin sizes the same,mabe a yamaha piston might work too??,
ina b/end bearing with outer sleeve?,bore/grind the honda rod to suit??,no need to reharden?