Swenracer,
I put Juliano's 3-point belts in my 56 and 57. It takes me about 45 minutes to install them. Drill 6 holes and I get shoulders on left and right side and lap in the middle. The anchor plates that come with the kits have rounded edged so they won't try to rip the metal and pull out in an accident. The force put on the anchor plate in a accident can be like 5000 pounds...I don't think the TF seat hardware is rated for that much strain.
Mike B
