I want to put circulating coolant heater on my 6h can a person T into the heater lines that run to the cab.thanks
Yes you can, if they run up towards the cab though the heat will go there rather than the engine. Taking the cool water off one heater line and the hot going into the block would be fine. You just have to understand how they work, most "circulating" heaters are only circulating if you set up the hoses right so they thermosiphon, you want a foot or more of vertical hose from the heater to the entrance to the block.
Ive got propane heater for out in the feid work was thinking of putting ball valve on one side so it had to do through the block one line comes from top of water pump and one off of back side of engine oil cooler it has a plugs but not sure if they are metric size on cat thats why i thought about the heater hoses.
OK, different animal than a tank type "circulating" heater. That should have enough heat output that it will be nice to have a little heat in the heater core to start with. Heater hoses should be fine, or you might find the thread sizes online and be able to order the exact fittings you need instead of teeing in. I wouldn't bother with the ball valve, see how it works, I doubt it will lose much heat to the heater core, or cause any loss of flow to the heater core when the engine's running.
Thanks for the info figured that should work but good to get some sound advice
I added a old crane under seat heater to my log skidder and I did just as suggested. I tied into the engine cold weather preheater heater and valved the engine heating line shutting it off when not heating the engine. It forces the heat through the heater core. Works great and with just Plexiglas stuck inside the protection screens as a crude and cheap cab it warms it up nicely.