I am scheduled for Monday morning. I've had the mufflers & "Y" sitting in a closet for some time now. If I drop .15 I will have to be pleased. Chuk, if you are talking about the drone issue I learned about the Borla's when working with Chrysler Conquests, one of the finest quality cars I have ever owned. I was told the hookers also do not drone. I and a few friends have used the Borla's with success, no drone and you are right, drone always occurs right in the rpm range where we cruise. I have used PYPES-took right off and sold, terrible. Flowmasters are junk baffled mufflers and good resonators are simply baffled boxes. I am old enough to have owned many V8 muscle cars including 5 Buick GS cars from a rare '67 340 to a few 455's. By the way Motor Trend tested the '70 Buick Stage 1 and it was the quickest muscle car they tested that year including the LS-6 460HP 454 Chevelle SS. Probably the one that would be worth the most now was a '69 Dodge R/T 440 4-speed drop top.
The quickest car I owned was a 2 liter Eagle Talon, no V8! Stutterstep launch at 10psi at 4750rpm netted the best 60' on street tires, a 1.68. 1/4 mile in 11.68 at 122mph. That car had 10 second capabilities (TURBO)from 122 cubes. That 2 liter was close to 500rwhp. Shifted at 8500rpm and bounced off the 9k rev limiter many a time and the builder, David Buschur, claimed it was good for 10,000rpm. Yes, I owned a Mustang with the 4v SC motor that put 440/440 to the wheels but I bought it tuned and did nothing to the motor but you seem to not want to let that car go. It was a crude car and nothing like the AMG I enjoy so much now. I have owned more turbo cars than V8's by a long shot. My first car I drove when I was 20 years of age was an 8 cylinder, a straight 8 in a '39 Buick Special!
I don't know what gave you the hard on but we once were almost friends with you offering to help with my car. I have had 4 back surgeries and need 2 more with a bleak future as far as that goes but I will make the best of it. Is it against the rules to say I am a Christian? I still hope to meet you and perhaps we can spend some time tuning my car as I have several to choose from.
I am looking for a 17 x 8" rear wheel with a 6.25-6.35" backspacing if anyone knows of one.

I'll be sure to give an honest assessment of the system I have chosen to try to coax the most power from a V6 motor and it's offbeat exhaust pulses.
Les, I would recommend that you add 18" extensions to the collectors of the long tubes you have with an x-pipe in that 18" section if there is room, you may find some of the power you have lacked with that system, couldn't hurt?