i just did this a few minutes ago while putting the finishing touches to a repaired plane. I changed out the landing gear, already had the smallest prop I could use on the engine. When I put it on the ground and raised it to level I only had about a 1/4 inch clearance. Going from a set of 2 inch tires to 3.5 fixed the problem. Last $* 60 I built used a Saito 100 and I used a 14 inch prop but that was about as long as I could go without changing the tires. Been a while and it may have had more clearance then that?