Hey guy's I'm looking at universal heater for my 2017 Z-FORCE 800. I notice some have a 5/8" diameter fitting for the heater core and some have 3/4". Does anyone know the inside diameter of the upper radiator hose? I'm pretty sure that is the hot coolant line from the engine.

[2015 Z Force 800 53/Trail EPS]

I've heard its either 26 or 28mm...which seems kinda big. Someone has to pull a hose and measure the inlet to be sure.