Add LS-3 to the list; cockpit is nearly identical to the LS-4. I'm 6'3"
and there was more extension in the seatback and pedals in my LS-3.
Though I'm thin (180 lbs.), the cockpit is wide.

But pay attention to the parachute. That can make all the difference.
Even the thinner chutes are often thicker behind the shoulders tapering
as you go down from there. I need the exact opposite to get in my ASW
24 (i.e., reclining further helps).

Also know that removing the seatback is a time-honored remedy for
taller guys in gliders like the ASW 20. And sometimes there are other
steps possible if it's close and the airplane is perfect in every other
respect. My 24, for example, arrived from the factory without a
backrest and it has the rudder pedals extended a few cm and an
aftermarket instrument panel that has higher knee cutouts. Later ASW
models are more accommodating.

There have been many threads on this subject on this newsgroup. Go to
groups.google.com advanced search page and search RAS using terms such
as tall pilot, big cockpit, etc.

Chip Bearden
ASW 24 "JB"