The original had spacers. Yes, the seat belt lug should be free to rotate.
Seat belt fitting kits typically come with longer bolts & stepped spacers.
Since fully tensile loading is usually difficult to arrange, a bolt in shear is far better than one in bending. Take a look at any OE seatbelt fitment…
I’ve got a continuing question on this topic. Securon belts.
The RH (US passenger) side fits well. But the other side is forced to fit at an angle. Now, the instructions address this but I’d like another set of eyes to look at this and see if it looks “right”.
Rotating the other way may seem better to feed the belt but the angle is even greater I think?
TRS responded and said that Spyder requests end fittings that are not compatible with shoulder bolts or step bushings. It appears that they intend for each of the 4 end fittings be bolted fast to the body mounting plates and their replacement crossmember.
I knew somthing was different with the mounting of the seat belt mechanism on my car and had chance to look when fitting the window motors this afternoon (see other post!).
On my car the seat belt mechanism is actually bolted onto the inside of the sill onto a heavy duty plate and at the top the belt runs through a heavy duty wire slot or “eye” which is bolted to the body where your mechanism is fitted. Consequently no problems with fitting. The belt turns though 90 degrees as it is pulled between the two mounting points.