My car is an early 22, which is to say (style wise) about the same as a 21, but has the 23's body structure (3 piece rear tub) with the exception that it has tack rails and not tack strips, like the 23.
Does anybody know where the rear seat springs fit, as in how far down from the top of the rear tack rail? I've never known for sure, so I took a guess and put them about an inch below the rear seat tack rail which made them level with that rail. Problem is, the upholstery covers I bought (from Classtique) won't go all the way over where I've got the springs now...so, I'm asking anybody here do you know where the rear seat springs are supposed to go?
I'm figuring that I if I lowered them I might get this blasted cover to fit correctly...Otherwise I've got to go back to Mike at Classtique and see about getting one that fits. Failing that, I'll figure a way to make this one fit by maybe sewing a couple of inches onto the bottom would workout well.
Martin, I can't speak to the original factory location, but here is what I did on my '24 cut-off touring (purists, avert your eyes).
I have long legs, so I needed to get the seat back as far back as possible for more leg room. Since my car was missing its wood support structure for the seat back, I made my own using 1/2 inch plywood for the vertical pieces. That gave me a little bit of extra room compared to the factory original slats.
Then, I used some strong wire to partially collapse the bottom part of the seat back spring pack, giving even more room. This also had the side effect of shortening the distance that the upholstery had to cover, which might help the situation you mentioned.
I hung the seat back spring so that the upper front part of the spring was approximately even with the top of the side wood tack strips. This put the bottom part of the seat back spring approximately 1 inch above the top of the seat bottom.
With these modifications, I bought myself an additional 2 inches of legroom.
See the attached pictures.
Mark, I wish I had seen this before I did my front seat...could've used that extra 2 inches myself (I'm 6.5). But you're right that might help with the rear seat too...also noticed that your springs are setting a wee bit lower than mine...you have the corners level with the tack rail, which was what I was wondering about in the first place.