1968 Volvo project Pure Volvocity

[68EFIvert]

I will be running Schroth 6 point belts when the car sees track day but I have a question. The dual lower belt that go under my body will need an attachment point. The guy that put in my cage said to tie a cross bar into the seat brackets. I used some 1/8" flat stock and 1/2" solid round rod to fabricate a mount for the belts to clip to. Do you guys think this will be strong enough for the purpose?

Here is a picture of the piece attached to the seat. Thanks for the help!