i recently purchased a deuce the prevous owner said it was a 1968 model. Althe ones that model year that i have seen had a differnt style heater it was under the dash and had 2 knobs. the heater in my truck is under the passangers seat with 2 hoses going into it. there is a little switch next to the glove box swich it to the left low speed middle is off and to the right is high. i have never seen this style before in any truck would this heater date the truck a differnt year?