To kill the drone in a dual exhaust system, you can play with the length of one of the tubes to put the exhaust pulses 180 degrees out of phase with each other. Then they effectively cancel each other out. However, it's probably easier said than done, considering how little space there is between the rear of the cat converter and the bend in the exhaust pipe where it goes over the rear axle.
If you have a mostly stock engine accept for simple bolt-ons you wont see the bennefit of LT's. The only way you will see big gains if you get the fuel curve remaped or you have a power adder. A mostly stock N/A car simple isnt flowing that much air unless its properly tuned. Otherwise there is no sense getting away from shorties. Which I'm gonna go back to or switch to BBK LT's....havent decided yet.
I think it is all a give and take. Some cars love them for some reason, some dont. My personal experience was this...
Shorties (Mac 1 5/8) H-pipe with cats (Mac 2 1/2) and the car ran a best of 13.89 @ 98.
Long Tubes (Mac 1 5/8) Prochamber (Mac 2 1/2) and pulleys, and the car ran a best of 13.05 @ 103.
I read the articles and take some bits of info, but I think every car is going to react differently for different reasons! My mild bolt on car LOVED the Long Tubes and prochamber, while some dont see any gains at all!