I replaced the old original dry rotted seatbelts with generic 3-point belts that I got from eBay. These seatbelts were designed for a bucket seat car that had the inside belt located next to the seat and didn't work with my bench seat with the bolt located behind the seat. This made the inside belt too short. To resolve this obstacle a set of lap belts were purchased from Summit Racing to replace the inboard belt. With the belt installed another issue came into play. Now the belt was too long. The buckle was almost at my chest instead of being at my pant pocket. I cut the belt from the mount where it attached to the floor and test fitted to figure out the correct length needed. After marking the length I took it to a local upholstery shop to have them sew the belt back on the mount. When I asked how much I owe they said no charge.
After I got everything installed and looking good I notice the shoulder strap was riding too high and cutting into my neck. I took the seatbelt that the reel attaches to back off and cut the buckle off the end of the belt and reinstalled the original drop extension, after I replace the webbing, to the roof rail and then went back to the upholstery shop and had them to sew the ends and catch back on the webbing. Again I ask how much do I owe and again they said no charge. The drop down extension fixed the problem and everybody lived happily ever after.
I used the parts left over from the two kits for the back seat. The back seat belts don’t have a retracting reel so they just lay on the seat. Both kits used the same style generic buckle. All of the seatbelt hardware bolted to the original location without having to do any modifications.
When I swapped from bench seat to buckets I used the plastic sleeve that came with the 3-point seatbelt kit. The sleeve keeps the inner belt stiff enough to latch the seatbelt with one hand.
The cost of the eBay belts were $33.95 each and the lap belt were $19.95 each, so the total cost for new seatbelts were less than $110