If you like the design of the 20TL and the look of one tip on each side go with the magnaflow catback.. from the pictures I have seen both outlet pipes exit the muffler on the same side, one just wraps around the back to exit the passenger side. Plus it's stainless and looks pretty nice.

look at the pic here:

http://www.magnaflow.com/02product/c...ks/pontiac.htm

 

Makes you wonder who to believe when they give you flow numbers. Here's some information from an exhaust company:


We have provided the air flow CFM for each muffler.
2½" straight pipes flow at 498.2 CFM &
3" straight pipes flow at 729.2 CFM.
A stock muffler flows at approx. 175-225 CFM.
3" mufflers will automatically flow at least 30% higher than a 2½" muffler just because of the pipe dimension.


If a 3" straight pipe can only flow 729.2 cfm, how can a muffler with a 3" inlet flow over 1100 cfm? Kind of makes you not trust anybody's information.

Jim, isn't your current I-pipe a 3" pipe that came with the Hooker exhaust? Just use that and put on a new muffler and tailpipes. I thought the only difference in the I-pipes was that the single cat cars had a longer I-pipe with the flange on it and the dual cat cars it was shorter with a slip fit connection. Therefore you should be able to use the single cat I-pipe and just cut it down to fit.

 

Sent you an email ...


Jim

 

http://www.dynomax.com/documents/ultrafloweld_specs.pdf

I wonder if it is how they flowed them as in using mercury or water and differant pressures?