[gearhead]

I'm not too crazy about self drilling self tapping screws. I would want at least 2 stainless steel bolts with stainless washers and stainless nylock nuts on each side. Then use the self drilling screws on any left over holes.
Drilling into the frame might be easy, or not, depending on the metallurgy and the heat treat of the frame.
I would have a good drill, maybe 1/2" and a strong nut driver for the self drilling. Might even plan on a floor jack to keep pressure on the drill, and oil to spray on the bit to drill through the frame.
Keep us updated.