flowmaster upside down or not

[99chevysilvy]

Like it says can i put a flowmaster upside down if i have to? Just wandering since they dont make the 40series orig anymore in center in/ center out, im gonna have to buy the offset in/ center out 40's and they might have to be turned upside down or something. Didnt know if it would screw anything up or not. Also what inlet's/outlet's will fit on a 99-04 silverado? Im going with 40 series orig. flows. 2.5'' true duals out the back or out hte sides behind the tires or run the pipes over the rear end and cut em off right after they bend over the rear end or run em straight out hte back and then in the winter time cut em off right after they bend and in the spring-fall weld the pipes and tips back on and then cut em off close to the same spot again in winter...????

[Shawn]

I think you mean backwards.... there's not really an "upside down" to it.
Flowmasters are marked with a specific inlet and outlet. Meaning that the muffer was designed to flow and work in a specific direction.

Hard to believe they've discontinued the centered in/out - at any rate, maybe you should shop around more, there are probably places that still have them on the shelf.

[LikeaRock14]

You can still find centerin/out 40 series origonals

Linky Link
It's a pdf, so you need Adobe to read, but its there

As for the locations, you still need certain inlets/outlets to fit the mufflers right when they're mounted. You CAN move them side to side. I/e left side inlet, turn it over for right side inlet lol.
As for inlet sizes, 2.5" is what you're gonna get. If you want 2.5" pipes, get 2.5" mufflers. The inlets can be expanded no problem to have them fit over the stock 2.75" piping.

Call a shop, or go to them. A lot of times, by the time you buy the mufflers and pay for shipping, and your tips, it might be cheaper to have the shop all provide it

[99chevysilvy]

I know they have a certain way they go and i think u covered it rock but what i mean was if the muffler is standing up and the number is on the outlet can i turn the muffler upside down that means the number would be up against the bottom of the bed instead of toward the ground. That is if i have to do it if i cant get the center in/ center out 40's. Does anyone know what inlet and outlet will fit on a 99-04 silverado?? Did u find that off of a a site called caraddons.com. If so i dont wanna pay that much.

[LikeaRock14]

As for turning it like that, it'll work fine

[99chevysilvy]

So the offset in/ center out flows will fit on my truck without hanging down too much? I still dont know what year im getting yet. Its been raining really hard here and **** and i think its finally gonna clear up so i can go look. But its gonna be a 99-04 silverado reg. cab or ext. cab swb auto 2wd or 4wd. But how does this sound -- Airaid intake, tb spacer, if used new plugs and wires and fuel filter, hypertech programmer( for now), then cut the factory pipes off about 3-4'' after the cats and run true duals from there no x-pipe or h-pipe -----(i think thats what causes drone and resonance in certain vehicles) ----- (does to a couple of my friends trucks after they added it) now back to my setup back to 40 series orig. 40's then back to the bumper with 18'' long 4'' out tips. How will that sound? Will that make me fast as my friends truck i have told about?? Especially off the line like his is???