Thinking of using Cadillac CTS seats like these. Have seat belts built in. $100 Ea at the scrap yard
They want over $1300 a pair for these used in the California AND on EBay. Plus, they are hard to find! UGH! I had the factory low-back buckets, but as I have built the car from a stock Slant 6 that wouldn't stop,, corner or even go very well a all, into something with 4 wheel disc brakes, chassis reinforcements, suspension, a stroked Injected Magnum with over 500hp/500 tq and a 4 speed automatic overdrive; I broke down and got some seats that will not only hold me in my seat while still being comfortable ( they fit up to a 42" to 44" pant size, I'm a 38" pant size now, but many of my friends are bigger guys), but they will also greatly improve my and my passenger's safety on the road & track. I have a convertible and a 4 point roll bar to boot, this option enable me to have a quality, modern, much safer seat and seatbelt/shoulder harness restraint system.
The nice part is that they bolt right into almost any known car with a custom mounting frame, even my 1968 Plymouth Barracuda. I feel it is money well spent on a safety item like this. I always worried about whiplash, face plants into the steering wheel and dash and roll-overs with the old original low-back seats and factory seat belts. They were a bit pricey, but I opted for the higher end of a wide product line with a lot of quality inexpensive options for every budget.
I bought mine on-line with no tax or shipping from RacingSeatsUSA.com. Great customer service so far!.
I sourced