I just went through this, best option upgrade the crankshaft to 3/4 for $25 then get the eBay torque converter. https://www.ebay.com/itm/HONDA-GX200-6-5-hp-CRANKSHAFT-FITS-6-5HP-ENGINE/220732473312?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649