What's the size on the dynomax catback for the a 91 350 with dual cats. Whats the size of the stock exhaust for a 350 tpi? At first I wanted a hooker catback and was trying to avoid getting flowmaster. Since hooker does not make a catback for my car without doing extra fab work, I went back to flowmaster. I then caught my self looking in Jegs, when I saw Dynomax make a cat back for dual cats for 161.99, hooker makes it for around 260 and flowmaster makes it for dual cat cars for 339.00 So now I have to pay the most for the exhaust system I dont want. Then I thought, why dont I get the Dynomax cat back and get a hooker aero chamber muffler which would make the total cost 277.00. I just saved my self about 60.00 and I get a sound I want. If anyone could answer the questions at the beggining of the post I'd apptreciate it. Thanks alot.

The DynoMax is 3". You cannot buy a 3" inlet crossflow Aero-chamber without buying the entire catback. Besides, even if they
did the mufflers are not interchangable without custom exhaust work anyway.

DynoMax does sell the just the I-Pipe, but I'm not sure of the part #.. I believe Jegs does sell a universal muffler with 3" inlet, but I don't have the catalog here, so I'm not positive.

I have the Flowmaster Force II dual cat system, and replaced the muffler with a Aerochamber single in/out 3" muffler. The Aerochamber muffler was slightly shorter so a stub had to be added to make it fit properly. Other than that, piece of cake. The muffler shop took the Flowmaster in trade for all the labor to install the Aerochamber.

I don't know about the Dynomax system but that would be another way to go if trying to save money.

Hooker 3", $200 for the old 4 bolt cat. Since you have dual cats, you'll probably need some fab work so cutting the 4 bolt cat flange off shouldn't be a big deal