I got mine from seatbelt planet and they were great to deal with.
https://www.seatbeltplanet.com/seatb...cts/25/view/63
140" belt length, with 20" adjustable buckle strap. Plenty long enough with my stock bench seat.
They came with heavy steel backing plates and Grade 8 7/16 bolts to install. I slid the plates up the B pillar for shoulder mount reinforcement.