This issue, in my estimation, is F5R's biggest failure. Who would have thought that they would sell you seats that don't fit in the car. Also, the seats quickly fade to a not-so-pretty pink color.
I pulled back the covering and cut out a section of the tubular frame to get the seat narrow enough in front to mount square with the car. Now I'm restricted to only skinny passengers. It's embarrassing to have to tell people that they are too fat to ride in my car.
If I were in your situation, I would take a look at the Kirkey's. I still plan to do this sometime even though I have effectively ruined the Street Performers.
Gary - The harder I try, the luckier I get.
Rebuilt carbed 302, Centerline wheels, Lots of donor parts, Lots of custom-made parts