We're talking fabrication here. IMO.

In Oakland, go to Conversion Techniques off of Bigge Ave. Ask for Dave if he's still there. They're Sparco reps- very friendly and helpful.

BTW, the clip in harness mounts re use the stock mounts for the lap belt; you have various options about how to mount the shoulder harness and optional anti-sub strap. Some require a roll bar with harness crossmembers, others will force you to sacrifice the use of your rear seats to accomodate the harness. The quys at Conversion Techniques will help sort this out for ya.