So looking under my truck I notice I only have about 2.5 feet of single pipe between the factory y where the pipes off the manifolds come together and where my duals start so my question is if I cut out that single and run true duals is there going to be any actual difference

 

Bump

 

I doubt that it would make a noticeable difference in performance. I wouldn't bother with it, unless you're already under there working on the rest of the exhaust.