You could always add a Mach 1 10r80 cooler. The Mach 1 cooler is located in the front right corner of the bumper. The engine oil cooler is on the left front corner.
I have a set of non R GT350 springs. They are in a box and I could send them to your shipper.
To my knowledge all GT350s had magnaride. Even non r 350s.
Here is my Facebook market place add for them.
https://www.facebook.com/marketplace/item/1101172018364322/?mibextid=6ojiHh
My car has had that stumble since new. It also on occasion has that same stumble when coming up to a stop light or at a light in traffic. It used to be worrisome, but I'm used to it now. Mine is stock with the stock tune.
I have a 1st generation Timpte 720 drop trailer. Their service is top notch. They send me whatever I ask for and are easy to communicate with.
They have improved the design a lot in their latest version that has me thinking of buying a new one.
Once in awhile it would throw a code the first 6 months. I haven't had one show up in some time now. I just have the extensions on the rear 02 sensors. No tune and no cats.
I have a full ARH system on mine and agree 100% the ARH system gives it more of the refined exotic flat plane crank sound.
In my opinion the stock exhaust tried to have a similar traditional coyote Mustang sound.