I cant remember exactly what the stock lug height is, but you dont want to be any higher than 3/8" over the lug. The tunnel coolers are not an issue as long as you lay out your stud pattern to avoid them. The bigger isssue is the front and rear coolers. You MUST have heat exchanger protectors FRONT AND REAR!!! If you fail to install these protectors, you will end up damaging them and probably end up walking home. These protect the exchangers from the studs digging and poking holes in your cooling system.