Jacques,
The CN Geeps were built into chop-noses in several classes. All were called "GP9RM", meaning GP9's Remanufactured in Montreal.
For road-freight service the engines were set up to operate short-hood forward, and rebuilt in 6 groups:
4000-4011, class GR-418a, 258 tons
4012-4021, class GR-418b, 258 tons
4022-4036, class GR-418c, 258 tons
3100-4116, class GR-418d, 247 tons
4117-4128, class GR-418e, 247 tons
4129-4143, class GR-418f, 247 tons.
Some were set up as switchers, and while they were marked short-hood as "Front", the control stand was set up for long-hood forward operation:
7000-7013, class GS-418a, 257 tons
7014-7043, class GY-418b, 248 tons
7044-7078, class GY-418c, 248 tons
7079-7083, class GY-418d, 248 tons
Also, several were set up as "slug-mothers", to be paired with engineless yard slugs. I believe these were also set up with the control stand for long-hood forward.
7200-7213, class GY-418a, 257 tons
7214-7231, class GY-418b, 257 tons
7232-7240, class GY-418c, 248 tons
7241-7248, class GY-418d, 248 tons
7249-7270, class GY-418e, 248 tons
7271-7280, class GY-418f, 248 tons