If possible you should switch to an 4120/18 or even a 2826/12 for your 5S pack. These will allow you to run more reasonably sized prop in the 13 -14 inch range.

I am using a 4130/16, 6S 4440 Tanics, 16*10 prop on a World Models Chipmunk 90S that weighs in at 8 pounds and it is not lacking for performance. The 4130/16 is more appropriate in a .60 size plane.

In very rough terms the 2826 is similar to a .40-45 two stroke, the 4120 is similar to a .45-.55 two stroke, and the 4130 is similar to a .61 two stroke. Actual results will depend on the battery and prop that are being used. However since the electric will use a larger prop at a slower speed it is more like switching to a four stroke. Less speed but more pull.