I have a 79 fj40 w/ 4 in' skyjacker, shackel reversal from man-a-fre, I believed it's 2 1/2'. The rear I have 2 in shackle. I have stock axles w/ 4.11's Is it hi enough for 37's Mtr's? Is it hi enough for 36's Swampers SX's? Are the axles up to hold together?