Assembled and reupholstered seats. Seats have been upholstered in a two-tone grey leather with a '63-style pattern.
In our last installment, we covered the engine, drivetrain, and brakes. we are busy working on the many remaining tasks for our project, but we thought we would cover one aspect of the interior that has drawn quite a bit of interest lately. There will be more on other interior features in a later installment.
If you like the style, comfort, and the ability of newer seats to grace your bottom in the manner to which it has now become accustomed, you may be considering upgrading/changing your seats. While there are aftermarket seats available, many folks prefer to use as many Corvette components as possible when modifying their cars.
Installing C5 seats is becoming a popular way to achieve those goals, but getting them to fit and mount correctly can be an issue. Having gone through that recently, we thought we would share the approach we took to install them in a '63 coupe. We found some C5 seats on eBay, and the ones we have seen range from nearly new and perfect to those that will require reupholstering. The ones we found were a little worn, but since we planned to reupholster them anyway, there was no need to pay the price for perfect seats.
The four front and four rear billet aluminum seat risers are made from1-inch-diameter stock with the front risers 11/4-inches tall and therears 1/4-inch tall. | 
This diagram shows the locations for the holes made for mounting theseat tracks. | 
This photo (front view) shows the front seat risers as installed on theseat frame. The 3/8x16x2-inches long socket bolts were used to mount therear risers and seat tracks. |
We chose to eliminate the power seat motors in order to lower the seats, eliminate the weight and wiring involved, and simplify the installation. To remove the power mechanism requires removing the seat bottom upholstery and foam in order to get at the four mounting bolts. At least that's what we did since we couldn't figure out a way to get at the bolts easily as they go into the power unit from the top of the seat frame. It isn't difficult at all, and you can put things back the way they were by reinstalling the hog rings at the rear of the seat and retightening the drawstring used to secure the seat-bottom upholstery.
For the installation, the main issues that need to be addressed are: seat height, seat rake, mounting, adjustability, and upholstery color match.
Issues
Seat Height: Installing C5 seats with their power adjusters in place can raise the height enough that you can hit your head on the ceiling of a coupe. The mechanism also weighs about 20 pounds each so you can save 40 pounds by eliminating them. If you want to retain the power feature, another approach is cutting and lowering the floors, but we didn't want to go that route.
On a convertible, you might find the seat headrests taller than you like, although we don't believe they are much taller than a midyear with the headrest option once the power seat assembly has been removed. If that is an issue for you, the seatbacks could be cut down somewhat to a height you prefer. If so, you will also likely have to move the seatback lock to a lower position. In a coupe, we didn't find height to be an issue.
Seat Rake: We found it helpful to raise the front of the seats so the angle of the seat bottom will help keep us in place and avoid the feeling of sliding forward.
Mounting: There are two areas to address here: Manual seat tracks can be fitted to the C5 seat frames, and the seat tracks need to be securely mounted to the floor.
Adjustability: Even without the power motors, the C5 seats retain their seatback adjustment. Most folks will also want to be able to adjust the forward and rearward position.
Seat Upholstery: You may be able to find seats which are fine; we've seen many on eBay. If you're lucky you might even find them in the right color to match your interior. If not, there are stock upholstery kits from a variety of sources, or you could go the custom route.