dssur
+1y
+45 at what width
+15 at what width.
Need to know widths, +45 on a 7 inch wide wheel is 5 3/4 backspace. +45 on an 8.5 inch wide wheel is 6.5 inches backspace. They have diferent frontspacing with the same offset, so one might fit, and one might not.
To quote backspace or offset you have to state width, or the numbers dont mean anything.
I had an isuzu once, and ordered 7 inch wide wheels with 4 3/4 backspace and they tucked great. That is a 3/4 inch offset, so +19 on a 7 inch wide wheel would work.
That backspace means anything with a 3 1/4 FRONTSPACE will tuck (7 wide + 1 inch for the beads = 8 - 4 3/4 backspace = 3 1/4 frontspace ) so you can figure out ANY wheel width. An 8.5 inch wide wheel wis 9.5 inches wide, - 3 1/4 = 6 1/4 backspace. To get offset from that number, 9.5 / 2 = 4 3/4 is the wheel centerline, 6 1/4 backspace - 4 3/4 center line = 1.5 inch offset = ~40 mm offset on 8.5 wide. With 20's though I would get as much as I could, so that should be the MINIMUM you should find. Body dropped maybe a half inch more to clear the inner bed side, or +52 on 8.5 wide.
Sorry for the math lesson but it really is simple once you figure out whats going on.