I have spent the most of the morning trying to find the answer using search and it unfortunately has eluded me. I am looking for actual dyno graphs of a 2.5 or a 3" true dual setup vs a stock 3" single or vs a cutout. I found one link but it was broken. Also, what is better the 2.5 or the 3" for most H/C combos. I'm just looking for a good solid answer on this.

 

As for the 2.5" vs. 3", most people will debate all day about this.

I prefer 3" all the way, but for people going over the axle, 3" up to the X-junction, then 2.5" on back works fine too.

 

2.5" unless you plan on having 500+ HP.

 

 

Exactly