Get the 14FF for the safety factor... if the axle shaft breaks, it will still stay in and keep you driving home. If 14sf axle shafts break, they'll slide out of the tubes just like a 10 bolt axle would. You really don't want that. I have a 14BFF in the garage waiting on lockers and new gears. I didn't want to buy new rims but it was a final decision, I had to upgrade to bigger axles and 8 lugs based on prior experience. Just my strongest advice to you, stay away from any type of semifloater axle...