Full size bronco coils on XJ

These aren't for my XJ, but I was wondering if anyone knew how much lift stock full size bronco coils give on an XJ, and how much stiffer they are. My brohter just completed his Nissan pathfinder SAS and complete suspension redo using 4.5" and 6.5" front XJ coils(4.5 in rear, 6.5 in front)...and they are WAY too soft, but gave the right height. So if the bronco's net anywhere near 4.5 - 6.5" on a cherokee(maybe even some lift springs), with a pretty stiff ride on a cherokee....that's what he needs. Thanks _nicko_

BTW, what are stock XJ coil spring rates? My brother just tried calling rockkrawler (the coils he's using) and they won't give spring rates(nice business they got going, have specially made parts and won't even give information about them), but said they are made to ride just like stock coils, which means close to the same rate as a stock coil. Anyone?