I did not drill a hole in mine. I just installed it the way it came. NVH is only noticeable on my car when passing through 40-45 mph and again at 70-80 mph, after which it goes away. If I had to rate it in terms of severity, I’d say it was 2-3, which is almost non existent.
FWIW, I bought this one. https://www.maperformance.com/products/superpro-positive-shift-mount-2015-mustang-s550-spf5061k It didn't have the surface area the CJ Pony Whiteline one had so I figured it would have less chance of NVH but still do what it is intended to do.
Pretty dang well! I bought a Pirelli Sottozero 3 tires (255/40R19 all around despite Bullitt calling for bigger back tires) and new rims to put them on. I think I used the snow/wet mode once when the snow was fairly deep and plows haven't made it our way yet. Haven't gotten stuck once and I don't recall any scary moments, even though we got good amount of snow this year.
Lowers the car about 3/4”. The ride is a little stiffer on normal setting. Sport and Track feel about the same until you corner aggressively, then the revised Magneride calibration, stiffer springs, and larger diameter sway bars make you feel like you’re on rails. The 3/4” drop is perfect imho
