Hey everyone I purchased these Moto Blue Underdrive Pulleys like a year ago and finally installed them "not on my truck", but on my mom's 04 Chevy Avalanche. It is pretty much stock accept for a K&N drop in filter, TB bypass, removed foam inserts and my old Hypertech III programmer.
Anyhow to keep the story short; my dad ended up with the pulleys for some parts swapping we did. So now the Pulleys are installed and is really noticeable when accelerating. Infact it is more noticeable on the 5.3 than it was when I installed a set on my old 90 model Chevy 5.7. Shocking! Not what I expected.
Just trying to get as much power out of her Gas HOGG Avalanche with out sacraficing MPG. Plus they are headed to North Carolina with the bike trailer and 2 Streetbikes... a lot of weight.
Anyhow I just figured I would post this note of info... my truck will be done in the future, but I am going to stick with ASPs.

 

You might want to check out Trick Flow...they have a set now, looks nice. I had the snap ring come out of my ASP - wasn't real impressed with it at that point or their refusal to replace it.

 

I hear you about the snap ring, but you seem to have been the only 1 that it hass happened too. Have you heard of anyone else with similar problems? I was on Summit Racing last night and seen the Trick Flow and the SLP underdrive pulleys. Everything I seen and read are the same as the MotoBlues. The only difference I have seen so far is the finaly color of the finished product: Nitride black, powder coated black and a zinc chromite. All 3 have the tall walls to keep teh belts from jumping off, timing marks if need be, same type of inner feeling, etc... I wonder who actually builds them and if I could order from them directly?