This is my first post on this forum in years, but I've had my viper since 2006 and remember reading this very thread in 2007 when I went to change my motor mounts. Well back then I thought that the 250 that Woodhouse got for a set was too expensive and so after reading this thread I decided to go with the polybushings less expensive mounts.
Sadly today I have to report that after 5 years approximately 20k miles later the polybushings mounts are flatter than pancakes they are completely shot. I also don't know how long they have been like this for, as I don't get underneath my viper and look around at it as often as I used too, but I'd be willing to guess that they've been worn out for a couple of years probably.
I went ahead and got the woodhouse mounts last week in the mail, and yes per Mark's reply in one of the responses the price had gone up, but if these dont' have to be changed out again later on, it will have been worth it. I'm not switching them til next week sometime but I'll take pics of the polybushing ones that come out of the car so people can see how they did after a few thousand miles. My guess without really knowing is that the heat from the engine was just too much for these mounts, I don't believe they were intended for the viper specifically and I do even remember having to put shims in as was explained here as well.
So long term even though the majority of this thread hypes up these polybushings mounts the overall long term results for me were not good.