Chris, weren't they only an option in 74, becoming standard in 75?
My 73 does not, and never did, have the drip rails...and you almost always get wet when exiting the vehicle in the rain. The trick is to open the door, wait a sec or two for the waterfall to end (it isn't really THAT bad), then exit the vehicle.
I prefer the cleaner look...so I say shave 'em!
...Jeff
'73 swb 2wd
'77 Blazer 2wd
73-87.com