Burr,
As you may know those are 2 completely different processes. The headers will improve air flow and allow for more fuel = power. Meth injection is a way to increase octane and therefore raise the ceiling for detonation. So if you have a high compression motor 10.5 on up, or running boost on pump gas the Meth which is about 108 octane will allow more safe power under elevated engine tuning, timing/boost/compression/cyl pressure w/o engine damage. I'm guessing that your 360 is a stock engine, is it a 5.9 magnum or LA 360? LA 360's are a very soft compression engine like 8 to 1 whereas the Magnum is about 9.6 to 1. The Magnum 5.9 would show some improvement in power if you ran a water/meth inj system due to the cooling of the air charge which increases air density and with efi it will compensate which will provide max timing and adj the fuel trims out as you are now fueling the car secondarily and still run fine. If it is a stock LA 360 don't bother really. It's just going to gurgle! On a lightly modded Dodge SRT-4 Turbo I ran Water/Meth on 18 psi of boost, stock was 15, and it made 15 horses, and 40 ft lbs over stock over the added 3 psi of boost just due to cooling. Be advised also that once the modded engine is set to run Water/Meth if it should quit and you do not have any fail-safes you will rattle the motor or melt a piston. On a stock setup there is no issue.
FYI,
Marion
