I can add from experience, If you don't use the reinforcement plates on the inside 4 bolts where they go thru the floor. They will cause fatigue cracks in the floor pans. I've bought parts cars where someone installed bucket seats without these plates, and have found cracked floor pans.
If you should need these plates, AMD makes these and are reasonable. Auto Metal Direct 407-1067-S: Bucket Seat Floor Mounting Bracket Set for 1967-1976 Mopar A-Body | JEGS
