The diamond stitching on the seat base is a "supporting net" with little give. so you sit higher than you would with a similar cushion w/o the diamond stitch. Try stacking a couple of spacer washers under the front of the seat tracks ( a couple at a time tilting it up and back some and see how feels. Option 2 is to have an inch taken out of the bottom of the seat cushion base. I know you'll be able to make an improvement with your above adv. speedster ownership skills .
I thought I was closing out this thread with some final thoughts and it turned into a completely new topic... funny how you guys so quickly create tangents.
I really don't want to cut any padding out of my seats and I love the diamond stitch. I can try popping a few more washers under the front to see what that does, but for normal driving around town its not that bad and I really didn't notice I was that high up until I saw the pictures with me driving it.
I guess if I really want to lower it, I could just bolt the seats directly to the floor, but that is very limiting on angle and no adjustment for people who aren't 6'2" like me.
Paul wrote: "funny how you guys so quickly create tangents."
You have no idea.
Some of our best stuff happens after all original questions are answered and the thread shows a propensity to drift. That's when we pounce and open up a whole new (probably unrelated) topic under the same header!
Trouble is..... That sometimes makes it difficult to do a search for stuff, but the search engine is up to the task.
A lumbar pillow is a MUST for "Speedster" seats and even then the seat is only good for about an hour before the aches set in. Try a rolled-up bath towel to get an idea of the size, shape and firmness that works for you and then either stick with the towel or find a pillow that feels the same. BTW: A rolled up towel under your knees at the front of the seat cushion does wonders, too, or a small gym bag on the floor up against the front of the seat to support your knees. I think that's a Jack Crosby trick, too.
I have a pair of roadster/cabriolet seats that increase the drive time to well over 2 hours before you need to get out and stretch and I have them mounted very low on a standard (not dropped) pan, but at 5'6" I am not "height challenged" as you giants are (just remember - It's always easier to look down while talking than looking up!)
The top of my head is about even with the windshield top frame. 
Thinner cushion, reclined seat (washers under the front mounting studs) both work, but the ultimate is to graft in a 2-1/2" dropped "paint tray style" seat tray to get your head down there.
@Alan Merklin I wonder, for height challenged guys like Paul and others, how difficult it would be to install a Convertible "D" windshield assembly to gain another 2"?
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It probably would not be an issue as you do not have to fix any windows but the top might be affected in how it is stretched or not stretched but Alan would know that. 
@MarylandGuy posted:I've dealt with lower back issues, and the accident in my truck last month didn't help.... The drive back was so long that my back spasms were back in full force for a couple days. All good now and its something I'm familiar with managing.
Speedster seats aren't exactly the best for lumbar support.
How about this?
If I was you, i would have the pan redone to lower the seat at an angle and put the seat right down with little or no movement or track. That way you can get it lower. i forgot the make of you speedster or whether you have a pan or a frame.
BTW Good Idea Danny, on the bottom or as a lumbar support
Thanks, Ray.
I second bolting the seat down and losing the track. It's you car, isn't it Paul?
Mine's bolted down. Others may regret that, but it fits me. So too bad.
On bolting the seat down in one spot;
I've found, over the years and with a LOT of multi-day trips, that it is sometimes helpful to be able to run the seat fore or aft a notch or two from time to time to re-adjust your legs and back and alleviate the aches and pains that inevitably show up.
I've also done the bolster under the knees thing and found that helpful, too. Haven't done the lumbar support towel behind the back, but I adjust the lumbar control in my DD from time to time and THAT makes a big difference, too. I think that inflatable pad that Danny found is really worth looking into, especially if you're planning on a day-long trip somewhere and especially if you have Speedster seats. My wife's Outback has an inflatable lumbar support with it's own little air pump!
Remember, the Speedster was a dream of Max Hoffman who wanted a stripped-down 356 for people to buy to drive to work during the week and race on weekends. They dropped a lot of weight out of the car for racing and the seats were lightened, too, but you're only in the car for an hour at most when you're doing club races, so the "Speedster Seat" made sense for them. They're far from the greatest on long trips.
@dlearl476 posted:From David’s OCD Machinist’s Guide, pp 412:
When spring washers are made, they’re stamped out of a sheet of metal. The stamping process leaves one radiused edge on the top and a sharp edge on the bottom where the washer finally tore away from the sheet. That sharp edge should always go to the hard surface that doesn’t turn, not the nut. It helps the washer dig in, like a star washer in miniature.
pp 112: Like washers, quality hardware nuts have a top and bottom as well. When I was re-doing my rockers today I noticed that the new adjuster lock nuts were 2-sided:
Top has the brand logo and hardness mark:
Bottom Is flat:
And, specific to these lock nuts, they are slightly tapered:
I tried and tried to get the best picture I could. You can see a slight triangle on the closest corner, and if you look at the two edges, you can see the taper. The narrow side goes down against the rocker.
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