2.5" exhaust will maintain flow velocity & will perform better in low-end & midrange...
We'll have to agree to disagree. Back pressure is bad and, even factoring in the tuning effect of the exhaust as a collector extension, 2.5" is too small, since 3" or 3.5" would be the size of the collector of the OP's headers.
Plenty of room for resonators in the tail pipes on an E-Body.
I've been giving that some thought on my Challenger, too. I like the better performance of the Ultraflows, but wouldn't mind toning down the sound level a bit.
