2 inch or 40mm depends which company you use is the usual gain with out affecting the travel to your bumpstops. To get the 3 inch i,m sure you really need to change your upper control arms for some new ones which help with bumpstop clearance, I went the cheaper end of the scale i got ironman full kit at trade price thats why i chose it, efs kits get a good review on here by the folks who have it