Bought new 2020 Tracker Classic XL boat & trailer package. Trailer spare tire mount is built inside fwd part of frame, under boat. I have bought a new tire, but cannot find the correct square u-bolt attachment to actually secure the tire & wheel to the frame. Ordered one from Amazon but wouldn't fit. Appears you need a square u-bolt with 4in inside width, @ 7in long and no taper. Any suggestions?