[Tom Goldman]

I'm guessing by your login this is an early B body car.
I've done many B body cars over the years with both Jaz and Kirkey seats .
While I prefer the Kirkey 55 series seats because I feel they are stronger ,I always have to bend the left side support out a bit to give more lateral leg movement and ease of entry /exit when using the narrower 17" seats that are common for F body GM cars ...The JAZ seat has the sides cut down lower and allows for easier entry and exit and more leg lateral movement.
On large cars such as a B body you can easily use the 20" wide Kirkey seats which will allow ample leg room without bending them out.