Outer Limits 4x4 Board

hey guys fittin up an lpg converter, and what id like to know is the best way to plumb it into the heater hoses,

also, is the heater turned on and off by a tap, or some sort of air flap thingo,

any help appreciated,

hey mate fit gas 4 a living
get a 3 way 5/16 barb fitting cut the two heater hose's going into the firewall with the hetaer changing look along those hoses and u will see the tap that adjusts hot and cold

thanks dude