The Faststrike (GL) model is similar to the older performance models called the XP/GT. These 150 models have a lot in common with the 175. Put out right at 10% more hp than the 150 on the side of the cowling. Makes about 165 hp. They all have the larger throated 175 carbs. Both 150 and 175 use the same heads. The main dif is that the 175's have a different block part number. Probably something to do with the factory porting.
