Seat foam

It can be bought from Legendary, but it is pretty pricey.

If you know what you're doing, or aren't afraid to try, you can go to an upholstery supply shop and buy your own foam. Glue it down and trim it with a electric knife til you get the proper shape you want.

Don't forget to check your seat for broken springs. No sense in recovering your seat and your butt still hits the floor pan. When I redid my seats, it seemed like my head was going to hit the headliner!!