"Flipping the axles" will usually net about 4.5". I think you've subtracted wrong, 57-54=3, he only needs 3 more inches. What is the truck model #? My 02 Chev K3500 isn't that high. Stock, my 5er sits about 3" front high when attached, however, it's also 40' long.
2000 Winnebago Ultimate Freedom USQ40JD
, ISC 8.3 Cummins 350, Spartan MM Chassis. USA 1SG, retired;PPA,Good Sam Life member."We the people are the rightful masters of both the Congress and the Courts - not to overthrow the Constitution but to overthrow men who pervert theConstitution. "Abraham Lincoln"