Bought a new set of 8007-84b screamin eagle slip on mufflers but could not install them as they would not "slip On". Used a lot of force (Hammer) but they are just too tight for the pipe to slip on. I was removing a set of MS-123 cycle shack slip on mufflers. Any one have a similar problem?? Harley tag on the box shows they are for all FXR models. I was installing them on my 1993 FXRS.