Hi I'm new to the site but I wanted to ask is there a big difference in the performance / reliabilty of UD pulleys. I know there has been a lot of posts about ud pulley's but I wanted to ask about the Roush pulleys specifically. Since I have a Roush mustang, I wanted to keep it the same by getting the Roush UD pulleys. Are these good in terms of their performance as compared to others such as steeda?
I just got my car a week ago and I plan on adding the pulleys, CAI and exhaust although I am not sure what brand CAI I will use or what exhaust set up I am going to go with also.
Thanks
I just got my car a week ago and I plan on adding the pulleys, CAI and exhaust although I am not sure what brand CAI I will use or what exhaust set up I am going to go with also.
Thanks

we dont have them here. most people either swap them out with te stock ones for the test, or some claim that their car will be a track only vehicle by then and dont care.
x or h mainly depends on the mufflers you run. one may sound bad with a certain muffler. for example, an o/r x and flows souns horrible, but the o/r h with flows is great. the x is said to give better gains on the top end, while the h gives more low end torque.