Thanks for this post Neil. I investigated that hole previously and it looked nothing at all like a seat belt attachment. It had no threads visible, and my convertible top folds down over. In fact I thought of drilling a hole in that area below it to clear the top, then inserting a through bolt with a large washer that the Wesco provides in their kits specifically for that purpose. That's what I did in my last project. However I found the reinforced factory bolt hole under the rear "seat" so used that.njoconnor wrote:For those (like me) who are not skilled at metal fabrication, but want 3 point belt systems, there is a (somewhat) factory based solution available. If you look closely at Yadkin's pix #3 and #4, one can make out a small circular cap on the plastic inner liner. Behind that cap is a factory installed threaded receptacle for the non retracting shoulder belts used in the Euro versions of the early/mid-70's Spiders. The shoulder belts were clearly illustrated in my original manual (but not in the North American insert, which accompanied it). I also recalled that my sadly missed 71 Coupe had a 3 point system installed by the PO, with the shoulder belt anchors in roughly the same position. The factory welded receivers accept the standard mounting bolts for seatbelts.
I needed the folks at Seatbeltplanet to custom adapt a retractor which would work in any orientation (not just vertical, as most do). Since I purchased mine, I believe Sbp now has a specific model for Spiders. I needed to cut away some of the plastic liner for the retractor to clear and swivel, but it works, even with the air deflector in place. Using A/R's metal shoulder belt guides to feed the belt over the seat.
This elevates the anchor point for the shoulder belt by about 6-8 inches, but still not horizontal. It's worked for me and Patty so far. Just another approach for folks to consider.
Neil
After reading your post I investigated those holes further. They are full of crud and rust which hid the depth of the hole and the threads and fooled me previously. They are, in fact, specifically for a seat belt attachment. But, with a dental pick, shop vac, WD-40 and a thread chaser should clean up nicely. In the Wesco kit are heavy angles that I can use to mount the retractor boxes directly to that hole. Although the convertible top will fold over that it shouldn't impact its use at all.
And since that reduces the angle of the belt relative to the seat guide, the vertical load on the seat frame will be reduced somewhat.
A better attachment point, thanks!
