What years? 35 Lightning ...
 

What year did they change the 35 lightning from a single step to the twin step?

What year did they go to a the deep step?

Late 99 model year Lightning name split that Model year the single step was renamed Executioner/classic deck the Lightning name carried forward in the twin step .

Thanks for the info Bob. It is looking like the deep/twin steps came about in the L's in 2000? What windshields did the classics have in 99ish?

Twin step lightning has alway had curved glass windshield or curved race fairing. Single step (lignting, classic, executioner) has the angled plexiglass or fiberglass fairing.