Is the open 3" cutout enough for my Maggie 6.0 setup?
Is the little Vibrant resonator hurting performance? (I really don"t like the sound of open headers and the resonator nearly eliminates the rasp)
Do I need dual 3" cutouts?
If its hurting performance how much do you think?

My exhaust consists of cheap LT headers with 3" Y pipe merging into a 3" collector and the directly into a 3" Vibrant ultra quiet resonator. Right after the resonator there is another Y pipe with a 3" electric QTP cutout on one end and a full 3" exhaust on the other. The way I look at it is with the cutout open its essentially dual 3" exhaust which I believe should support my setup just fine. The restriction would really be the 18-24" of single 3" between the Y pipe merge and cutout.

I know that the full 3" exhaust with an OEM muffler will obviously hurt performance but I don't care that just for when I want to act normal and not have a headache.

 

I would want dual 3" to a single 4" or dual exhaust on it personally.

If you want to keep it low cost do a flowmaster dual 3" to single 4" with a cut out, then reduce down to your 3" catback.

 

I say dual 3” setup

 

My biggest concern is keeping it stock quiet with the cutout closed which it currently is. I also do not want the cut outs to be straight open header because then its just to much to drive around on the street with even in short bursts.
Also due to my ladder bar setup dual exhaust all the way out the back is pretty much impossible.

How much power do you think is being lost right now?

Here is my next thought.

 

But I really like the idea of dual 3" to single 4" then neck back down to 3" or find a 3.5" muffler off a 6.2 truck.

I could run a 4" diesel muffler as a resonator before the cutout to knock it down just a tad.

More art

 

I like your last 2 revisions.

If you could do dual 3" with mufflers you are okay with that would be best, but gotta work with what you have space and $ wise

HP loss... through single 3" is probably considerable but I would be just purely guessing.

I can say that even with my mostly stock truck I picked up 3 mph going to a straight through muffler and deleting the flap, and that was when I had stock manifolds and cats still and stock 5.3 catback.. Thats at my 1000-1000 ish foot test spot that's uphill.. Not scientific but it's a test spot.. And that's making a lot less power than you are.

 

Another idea is you could do two 3" resonators before the dual 3 to single 4 and a single straight through large case 4" muffler with no cutout and that just be your exhaust.

If it's too loud add a cut out and put a stock muffler behind the 4" muffler.. That starts getting pretty complex though.

I don't think a single 4" resonator or dual resonators off the headers before the cutout will quieten it down much though.

 

I think I'll buy 1 more 3" resonator and run them before the Y pipe merge to 4" and then a 4" cutout and then neck down to my current oem cobbled together system.

Then I'm only out the price of a resonator a dual 3" to single 4" merge pipe and a new cutout + labor.

But this will be a while since oem drive shafts need to be deleted first.

 

I hear ya, when you get it done post lots of sounds clips, I wanna see it and hear it

 

Cant have your cake and eat it too if youre that worried/annoyed with noise. Either loud and more hp, or decently quiet and forget about the slight hp loss.
just a guess but youre probably only losing 10-20hp thru full exhuast as long as that muffler isnt super baffled, and 5-10hp with cutout open imo which most people cant even tell the difference. You dont mention cats and thats the real hp killer.
get a full 4” diesel exhaust from the first y back and leave the cutout off, win win less to mess with.. my 2cents