Put in several sets from various vendors and didn't notice any problem with installing any of them. As I mentioned in another thread, a little wipe with some engine oil will help rubber slip in and it's absorbed in short order.
DG
Or a water-soluble "personal lubricant" like Equate Jelly at Walmart. It is the only lubricant that I use on rubber truck parts (not knowing the formulations of the various rubber parts used on a truck, it might be slightly risky using petroleum-containing products).
