dirthead,
With the quiet cores in the power is great and with them out the difference is very minimal, if any.
As to the quality on the pipes good weld jobs, excellent routing. As to the repack I'm not sure you have to ask them. No rejetting necessary when you take the quiet core in or out.

 

They sound like they would be an excellent choice for a pipe set-up...a little pricey but probably worth it.Do they list a horse power increase or a dyno chart with the pipes..???

 

i think LTE Claims it at 13 more horse power im not sure