I replaced my seat springs with plywood to save space only to realize later I'm going to have a gap, when upholstered. Im thinking, redo the back. longer this time, put in at a angle to cover the stock seat hump . or maybe put a plywood "lip" in to cover. any thoughts?
Yup, install at an angle, by the time you get some foam on there, it will look fine and be comfy. How tall are you? I'm 5'10 and we built my seat from scratch to sit down and back in the roadster.
Here's a crappy picture of what I did, I moved the wood support structure to the front of the hump which allows the board to hang over. The seat back has T nuts in it that allow bolts to pass through the wood support and hold the seat.
I would say to redo the top to cover the humper, if not I think you could feel it and It's in the lower part of your spine so I don't think it would be comfy, Did you make the seat pad grid fabric thingys or did you buy it? I need some, I guess I could make it.
Ok, so here's what I did. We built a modified seat riser (which we're going to begin manufacturing after the first of the year), then covered it with plywood and foam. Like I said, it puts me down and back and a pal of mine who has just about the same set-up (he's 6'4") has 100,000+ on his '29 roadster. Here it is covered (now has vinyl on it). But, it gives you an idea of how the seat is shaped. The back disappears down behind the reveal. But, it also has some lumbar support for the long drives. Was super comfy down and back to CA a couple weeks ago.
Here is what I would do 1. Remove the metal panel from the bottom of the seat back floor. 2. Put you seat back up under the rear of the body and slant it to come close to the seat pan. 3. Move seat pan forward a bit to make a longer seat bottom. I did this on my 28 and it is very very comfortable I used "hard" foam for the seat bottom 2in with a 4in roll in front. Sides and back are simular looking to a bucket T but the back has 2in of hard foam because it is tucked up under the panel. This allows me to sit on my legs not my tail bone.