Need a remedy for trailer porpoise. Using extende cab chev.pulling single axle trailer with 3100 lb 185. Im second owner and boat has always been on this trailer and appears to be set up correctly. Boat extends about 8 inches past bunks at the rear. Does have room to move front roller/crank fwd some. Had dual axle with other boats previously and no problems. Does someone have a solution to this problem . Afraid strap is going to break or bunks split. Other note,good shocks on p.u. Thanks