You don’t necessarily need the tall pentroof valve covers to work with stock Ford adjustable rockers, but there are some Ford valve covers that won’t work as-is.
The common ‘65 to mid ‘67 short angular FE valve covers won’t work. Some people mistakenly call those “pentroof” but they’re not the same as the tall pentroofs.
The early round top & “baldie” valve covers will work. And like Mike said the mid ‘67 & later “Powered by Ford” valve covers will work.
If you start adding aftermarket roller rockers then the choices can get more complicated.
