boat fenders

Boat trailer question?
Trailer: 13″ rims 5 bolt, galvinized.1.5 x 3″ frame. Problem: Boat rests on 4 bynks only. Keel dosent make it to the keel rollers. Cant lower bunks any more because bottom of boat hits top of fenders(replacing). Is there keel roller brackets avaiable with more than A 5″ rise? Or is it possible to go to A 12″ wheel to lower the fenders? 3000 lb. boat
Why worry a lot of boat don’t touch the rollers> The roller are used when loading & Unloading> If you want more support make the bunks longer>
StowAway Boat Fenders