After the impressive showing of the 1968 T'NT 600 on the race track. The new T'NTs for the 1968-1969 snowmobile season sold out before it even arrived. There were two new model's with new engines for the 1969 model year. One was the T'NT 399, the chassis was a slightly modified Olympique. The other was the T'NT 669, besides having a new engine, it also shared the chassis of another new arrival, The Nordic. Both engines were fan-cooled and had a single Tillotson HD carburetor. Available for the 699 was an intake manifold that would allow two HD's to be mounted, one above the other.
The new engines had a two piece shroud that deflected the heated air from the motor away from the driver. One of the problem's that the T'NT 600 had because of the engine being so close to the driver. The T'NT 399 had a the fimaliar air intake openings and a large black dot on the hood. The T'NT 669's all new chassis made it so that the sides went up to about the height of the seat. The hood wrapped neat around and connected at the front. There was also a T'NT 399 (model# 6944) with a 18 inch track.
The T'NT 399 dominated their classes, but the T'NT 669 had a rough season because of their class. Having to compete against the 800cc sled's, the displacement it give up was huge.