A friend in HS had a new 383 4spd 'Cuda. Worst seats ever!
E body seats are the most uncomfortable & least supportive of all seats. They are way too flat with no bolsters on seat cushion or seat back & therefore provide Zero side support in turns. You might as well put in a Bench Seat as they have the same support. NONE! If you want road race handling, forget them.
I have 86 BMW 318 Sport Seats in my 65 Barracuda, mounted to original adjuster tracks, & mounted same height in car as original buckets(not much bolsters to 65 seats, either).