I bought the heater unit off ebay. Do an ebay search, Astro Van Aux Heater. I just look at ebay, and they have gone up in price. Now around $71, but that is for the complete unit. Fan, heater core and shroud. This is a nice unit at a reasonable price. My cab is a soft side cab, and is not weather tight. However, makes it nice and cozy inside, while moving snow. The hard part was configuring the plumbing, and buying the fittings. The inlet and outlet on the heater core are 3/4, and I ran 5/8 off the rad hose, because that was the size of the T. I ordered the heater hose kit, (no hose, just T's) from my Kubota dealer. If I had it to do over I wouldn't order from the dealer. I searched the net and found what I needed, after I bought the kit. As I said, I used pipe to get the coolant by the muffler. That worked out nicely for me. O'Reillys's Auto Parts had most of the fittings, and some were from Ryder, off the net. javahjoe, MIO P K Junky, aka Don