Yes, to mount the 5point seatbelt harness correctly you will need to anchor them effectively which will involve plates either bolted or welded into place where the bottoms of the harness attaches. Your tops should attach to a rollbar for its intended original purpose but you can fabrictate from your existing rear struts to do this too. Appears you are going to be thinking about this one carefully. Goodluck. shane-
the shoulder straps from the seat back should be on a 45 defree angle, otherewise the stress from a collision can snap your chest bones like a toothpick. But that is written in the harness manuals. You also are recommended to use grade 8 or better bolts.
If you are using stock seats you will probably find that the belts will sit quite uncomfortably on your shouders. I hade my upholsterer put in snap straps to keep the belt in place.
Hope this helps.
Please oh please take a look at what you asked!
Follow the instructions given by the seatbelt manufacturer TO THE LETTER!
Welding is not required in many cases, just that you have sufficient doubling of the attachment point to prevent tear-through. In many cases, the Stock seatbelt anchoring points are NOT acceptable for mounting of the lap-belt portion of a multi-point restraint system! They all come with instructions, and offer technical support. Diest, Simpson, Schroth Those systems are in my cars. They are all outstanding.
When thinking about seatbelt anchoring, keep just two words in the back of your mind: "DALE EARNHARDT"