Please don't dishonor this beautiful bird by putting a 4 stroke in it. I would recommend the MVVS 77 set up as a rear exhaust for this bird. The MVVS 90 or the JETT 90 would also work great. It should have plenty of power and will also swing a bigger prop. The one problem you will find with bigger props on this plane is ground clearance so plan ahead. Remember this plane was designed to go fast and do big maneuvers, a 2 stroke turning higher rpms is more suited to this application.

If you insist on putting a 4 stroke in it,don't, Please pack it up and ship it to me. LOL