Jack,
We're the ones that originally started the "Sidepipe Modification" craze. The reason is simple...Horsepower!
We built a very, very strong 460 engine that should have dyno'd well over 500 plus horsepower. This engine was dyno'd numerous times. Adjusting timing, jetting the carb, changing cams, massive head work, etc., ec. All was a disappointment. Finally looked at the stock side pipes, cutting them apart.
Shocking, just shocking! Those stock 4" sidepipes, are actually two 1-inch (+/- can't remember the exact size now) pipe installed parallel internally. (One inlet, one outlet)
The search was on! That's when Lucien was located.(Forgive me if I have this wrong, but I think it was CobraEd that actually found the manufacturer - we were ordering them from JC Whitney!)
The old bullitts were cut out, new ones installed, welded, ground down and re-coated. Horsepower increase was (from memory again) right at 45 HP on this big block! We finally obtained our goal!
The torque readings went off the scale! You wont need to change the motor set up at all, but a one size larger jet, and a couple of degrees i timing, and you will swear your small block grew up!
The sound is more "deeper than louder", although it will be somewhat louder, but certainly not obnoxious.
I can't find the old thread here on the board, but we did have a full photo display with complete instructions on how we do it. Not hard really, after you cut the stock bullitt out of the pipes, bolt up
the collector to your headers, then take the "turn-out", bolt it up to the rear, then simply hold the new bullitt in place and tack weld both ends. Now you have a perfect aligned side pipe and a huge increase in power!
If you have any questions, don't hesitate to ask! This is almost becoming a "Must DO" mod to any Cobra!
DV
P.s. just went back through the archives and found the entire 4 page thread on this. Unfortunately the photo's are missing
http://www.clubcobra.com/forums/show...5&pagenumber=1