My dad purchased an 03 Kodiak 4500 late in 03. Kind of a funny story. He ordered it, it came in and me and him rode the truck and chassis around all day. Late that evening I noticed the the truck didn't have any AC controls inside. Looked under hood, no AC! Dad was furious, truck had been purchased. Anyway, dealership ordered him one with AC. Here's my question, the 1st truck seemed to have a tow/haul mode built in, it would downshift alot earlier in order to slow itself down. Kind of like when I put my truck in Tow/Haul mode-Kodiak doesn't have this on the shifter. The new truck shifts just like any other truck without using tow/haul mode, really no engine braking at all. Is this some option on the Kodiaks? Is there something I can change or wire up on the 4500? BTW it has the lb7 duramax and allison trans.