I've had issues with pedal arms hitting the frame when playing around with front sprockets and arms so take that into consideration.

You could also get this freewheel, your current one more than likely only goes to 14 tooth. This is the only affordable freewheel on the market that will bring it down to a 11 tooth which makes a huge difference. I forget the website where you can enter all this in to calculate speed but there is one.

https://www.amazon.com/gp/product/B07XYPH5BG/ref=ppx\_yo\_dt\_b\_search\_asin\_title?ie=UTF8&th=1