ive got a 05 screw 5.4 and i want to put pacesetter LT's, maggie high flows and the 11" maggie and an H pipe.

plan on going 3" from the lt's through the cats and to the muffler. then go 2.5" from the mufflers to (if it will fit) side dump infront of the rear tires with a 2.5" dual tip on both sides

question's
Do you think I'll pass emissions
Whats the 3" high flow cat part # i need to use
Which offset for the muffler do i use??

 

So you're wanting dual exhaust?

 

headers passing emissions, doesn't always happen, sometimes hi-flow cats barely get by depending if the people are d**ks.

One thing I disagree with on your planned system, dont run dual 3" pipes, have the ends of the headers downed to 2.5" and run a 2.5" dual exhaust. That will retain decent scavenging. And if you didn't know, after you modify headers, you need a custom tune.

 

what exactly is scavenging? never understood the term.

 

do i have to have a tuner like a gryphon to get a custom tune or do i cary it to someone who has one??

 

Its the pressure flow of dual exhausts, need to be at a good pressure and flow correctly to re-tain great low end torque.

Custom tune would be best, so you can actually have the exhaust programmed in to perform at best.

 

I would run 2 1/2 pipe thats plenty, and X-pipe with 2 mufflers, I have mine setup like this and I pass emissions every 2 years, I had the 14" magnaflow DIDO and to my it was WAY too loud and I have dynamat all over my truck.

 

i thought for an X pipe to function correctly it needs to have equal lengths of pipe before the mufflers on both sides.

i haven't relay looked at it to good, but is there enough room under our trucks to run the pipes out INFRONT of the rear tires on BOTH sides

and what offset for the mufflers do i need to get

 

there is no reason that there shouldn't be equal length of pipe between the x pipe and mufflers

 

Not to the left side due to the fuel tank. Plenty of room underneith for true duals X piped. I thought you had the 11" DI/DO planned. If your gonna exit them passenger side before tire, I would get the centered inlet offset outlet. Thats what I got, but only because my installer didn't install them the way I requested. Magnaflows are direct flowing so they are interchangable, thats why he flipped them around. But with the way mine are, it would be much easier and direct to exit at the before tire.