I don't suppose anyone is familiar with the Honda 20hp GXV620 engine? My father in law has this on his Hustler fastrak 52" and would like to be able to do the same upgrade as we did on the Kawasakis.... I had no time to dig deep into this, but at first glance looking at the owners manual, it may be similar to the GXV670 24hp model... both are 614cc. Maybe I need to start this in a new thread. Chime in anyone with any info.