Ramcharger exhaust 2-1/4 duals or single 3"

Just as an example and not a direct apple to apple comparison.... on my old ‘79 Magnum, fully loaded minus the moon roof w/a 360/904/8-1/4 w/2.76 gears on 26 inch tires weighing in at 3800 with very little fuel.....

I added/changed some parts to the 360. The stock cam remained but swapped on a factory iron intake and a 600 Edelbrock. The exhaust off of the manifolds was at 2-1/4 with an H pipe before the twin high flow cats which were legally needed at the time into turbo mufflers to the bumper.

All in all it was a nice but modest gain. The engine was Chrome box triggered at first but then switched out for a MSD 6A. After much attention was applied to tweaking the best I could get out of it mileage wise (the primary side of the carb of course) I managed the best of 20, though 19 was most consistent. The MSD was responsible for some of that mileage. Approximately 2+ mpg were found after more tuning.

It did pass emission testing very well. The testers were even a bit confused and hesitant to let it go out the door asking a bunch of questions and wondering why it was passing as almost a brand new car.

Now I do realize that there is a bit of a weight difference as well as a aerodynamic difference in a big way, but as I said, just as an example..... tune away! Keep on it. Finding what your looking for can only so good but get it as good as you can.