My passenger sun visor on my 1977 G10 is falling apart and I was searching on ebay for replacements, or going to go to local junk yard to pull a visor. but before heading out i did some research

The thing is my van is a 1977 but on ebay I only see listings that say 1983-1995 Chevy G10 G20 GMC G15 G25 Van SUNVISORS

Does anyone know if they changed the design in 83 and if so where to get an older one? junk yards sometimes have older vans but right now only have mid 80s and some 90s models on the lot.

if the newer visors are different do people drill holes to make them fit? any thoughts appreciated.