Need new suspension
No, just less torsion bar preload. My car is about 1/2" higher than 72blunblu's and I still have the ability to go down with less preload without even trying.
The problem isn't the torsion bar adjusters, it's that you run out of suspension travel. Even where my car sits I only have about 1" of suspension travel from the bumpstop on the LCA to the frame.
I am going to do new torsion bars, shocks and sway bars. So would I need to use drop spindles in order to maintain the same ride height?
As much as I dislike them, I would say yes, you'll probably need drop spindles to stay that low.
My car sits at 24 7/8" at the wheel opening now, and that's with a 25.6" tall front tire. With my bumpstops changed out to 3/8" tall poly buttons, I have 1" of clearance from the top of the bumpstop to the frame. Even with 1.12" torsion bars (300 lb/in wheel rate) I occasionally bottom the suspension out on big potholes, etc. I don't need to raise the car any, but I'm pretty close to as low as I can go with the torsion bars that I have.
Now, a small change in distance at the LCA is much bigger change in distance at the wheel opening. But considering you have 26" tall front tires and want to run smaller torsion bars, I'd say you'd need more clearance than I have, not less. I've never bothered to check the exact relationship between the change in ride height compared to the change in clearance at the LCA. With the difference in tire heights I'd have to drop my car a full inch to be where you're at, and I don't think I could pull that off without being on the bumpstops frequently under normal driving conditions.
The only other thing you could consider doing would be changing over to the QA1 tubular LCA's. Because of their tubular construction their height profile is shorter, which basically means you get more suspension travel before they bottom out when compared to the stock LCA's. That would still leave you with a more severe angle on the UCA's though. And the additional travel might actually lead to interference between the top of the tire and the inner fender at full compression. Which is
definitely an issue you can run into with the drop spindles too, by the way.
I have a set of the QA1 tubular LCA's to put on my car, haven't gotten around to doing it yet. They're going to go on at the same time as my new SPC adjustable UCA's so I only have to set the alignment once.