to my knowledge, the KB167 is not made for magnum motors. magnum and LA motors have different widths on the little end of the rod, and thus the piston pin boss is narrower or wider to accommodate.
it's not clear: are you building a 5.2 now or are you building a 5.9?
I'm building the 5.2 now, well I sure hope that's not the case uempistons.com shows the product to fit a 5.2 magnum and can be either pressed or floating, not saying your wrong just stating what the website says.