Hi does anyone know whether a Q16XL is shaft drive or belt drive and vertical crankshaft or horizontal
Hi would that deck 14002 fit an st160Yes, that is definitely a G16XL. The XL tractor has a front mule drive to run the belt from the electric PTO clutch down to the mower deck.
The mower deck that you have pictured is not correct for the XL tractor. It is a newer mower deck for the ST series lawn tractors, which had a vertical shaft engine. Looks to be a 42" rear discharge model 14002. The mounting is completely different, as is the belt routing.