I use an OS 91 FX on mine and am pretty happy with it. It won't climb out of site in a vertical climb, but in Sportsman pattern there isn't any need for a very long vertical pull.

Lots of people are putting an OS 120 AX on them and seem pleased.

I think the gasser will be too heavy as it is 7 ounces (200 grams) heavier than the 120 AX.