'67-'68's don't have as much room in the wheelwells as the '69's do,the fitment you have works well on most all '69 models but all these cars are a hair off being mass-produced.
What size tires are you running?Spacers will probably cause you problems with your outer fender if you space them out too far as well...
First,find out exactly where they are making contact...might be something as simple as beating in the inner fenderwell with some heat and a BFH and voila...problem solved.
