Help with exhaust

ok so i have a 1999 chevy tahoe 4 door 2WD. I want to spice the exhuast up a little bit with a glass pack (yes i no u guys like flowmasters but im not gunna keep this truck for more than 2 years). I don't want a muffler shop to do the work...i wanna do it. I am trying to do this the most cost effective way possible, that's why i am not installing new pipes, just using the existing. So if anyone can help me i would appreciate it.

Plan:
1. I was going to cut the intermediate pipe right before the muffler.
2. Put on 2.75" to 2.50" reducer (glasspacks don't come in 2.75")
3. Put on 2.50" glasspack
4. secure with band clamp
5. on the other side of glasspack, put turndown exhaust pipe
6. secure with band clamp

Will cutting the intermediate pipe before the muffler work or do i need a Y-pipe?

ok... well theres one problem.. there are two pipes coming into the muffler.. - you need two glass packs.. and then the U-bolt clamps that they sell at auto-zone.. and then you need something to hang both of them from like muffler hangers.. (coat hanger what ever you desire) and than if it leaks any.. thats when you can take it to a buddy with a welder or any decent exhuast shop would only charge (should charge) $15 bux to weld it up
but you got the reducer part right.. (i guess?) is it 2.75... or closer to 2?

my truck has two cats. They combine together and only one pipe goes into the muffler and one out.

and no i dont have the reducer yet. its a 2.75" OD to 2.50" ID reducer.(http://www.ecklers.com/product.asp?pf_id=38158&dept_id=159) Can u think of any other way to do it? Possibly buy new intermediate pipe that's either 3" or 2.5"? I only decided on using a reducer because it seemed like an inexpensive way to allow my truck to have a glasspack on it.

Here you can see the 2 cats and how they converge into one pipe


Here is another view of how the cats combine into one pipe


Here is a view of how the single pipe from the cats goes into the intermediate pipe


The right side of the pipe is exactly where it left off in pic above. This is more of the intermediate pipe


Then that pipe goes into the muffler like so...

I really like your exhuast.. i've never seen that on an OBS.. i really don't think it is factory.. usually both cats are on the pass side only.. with two pipes runnin into the muffler one out.. but, some exhuast people did a good job gettin that cat on the other side like that... thats pretty nice actually - but no.. only way really to do it by yourself w/ out any muffler machinery around (like a pipe flanger etc) would be just to get the parts from autozone and clamp it all down, and try your best to get some kinda muffler hanger mocked up.. (you can get the hangers at autozone too i belive the bolt on kind...) and then later down the road just take it to an exhuast shop and have them weld your reduce to your pipe.. i mean it literally should cost like 15 bux to have them weld it on.. ... i still like your exhuast.. i'm jealous..

--edit-- bump that.. upon second look of your muffler.. it has a hanger welded on before the muffler...so.. just cut about 3 in. after that hanger and put the glass pack on.. and bolt it all down tight.. than try to move the end of the glass pack to see if it does move at all (might want to get a tourqe wrench or an air-gun to tighten the u-bolts down tight)

but still i would think about having that reducer flange welded on down the road.. than u could take those u-clamps off.. and it would be pretty good and tight than

i dont think im going to have it welded b/c it adds a lot more complication and its permanent. Im just gunna use band clamps to connect reducer to muffler and muffler to turndown pipe (http://www.jegs.com/p/JEGS/753274/10002/-1/11527). and im gunna use this clamp for the intermediate pipe to reducer connection (http://www.jegs.com/p/JEGS/1020036/10002/-1/11527). im definitely gunna add a hanger after the glasspack...i dont wanna lose it while im driving.