how much pipe between muff and cat?

[tpichevy]

ok so i just got my magnaflow muff from the GP!! im goin to swap it out with my 40 flomaster, its a 3"in/out and i want to run it out like the foed lightnings...bring it out in front of the back tire and cut it on a 45 angle, im thinkin i will need to mover the muff closer to the cat. here is my guestion....is there an amout of pipe i need to have between the muff and cat to keep the performacne fine and or to keep things workin? also will i run into any other problems by runnin this muff out like this? its goin on a 92 5/7 drop built TPI short bed reg cab truck!!

[YenkoST]

No, you can put the muffler as close to the cat as you want. It makes no difference and you can even move the cat/cats closer to the headers if you want.

[vic_V8]

The only thing it MIGHT change is the exhaust note.