hey, i gotta 65 coupe and im thinkin of putting some big wheels on, i saw some chart also the dodgestang 1 that said 18" wheels fit. im gonna roll my fenders and whatnot, but if i were to get 18x8 ( rear ) with something like 245 35(or 40) 18 and 205 35(or 40) 18 or 17's in the front, i've got stock stock springs and leafs. i was wondering what "offset" i need and wether i will be fine... i've looked on wheel web sites that say an offset in mm's arround 20-40 etc, but i have seen 4.5 inch back space clearance, whats the diff between those? thanx for help and whatnot :\.