getting ready to decat my 2010 RK has anybody welded in something but left maybe 3-4 inch "power chamber" in the stock exhaust just thinking

 

Not clear on what you're asking - are you wanting to try to modify the current pipe to make an X pipe after you remove the cat?

 

yes that is what I was thinking X pipe style

 

my $0.02 - not unless you have some proven design that works...otherwise, its a recipe for disaster...

 

I welded a straight divider plate in one didn't notice any difference really. Thinking of putting 2 short pipes in one sometime just haven't messed with it yet.

 

I think if you were to separate the 2 pipes with a plate or weld in 2 pipes it would almost be a true dual setup !!

 

Look at the Fullsac sportpipe.
http://www.fullsac.com/sportpipe.html