You can, personally I find them to be a PITA to adjust, but some guys are ok with them. With the difficulty in finding adjustable rockers now, its an option worth considering.
I wont use an adjustable pushrod...... in a 5/16 they are very thin wall around the adjuster and prone to failure.... so NO
I'd like to correct false info....... "difficulty in finding adjustable rockers"....... Is not true.... Ive plenty of Olds rockers on the shelf , straight 303,324,371 as well as the offset for 394 ....because we sell quite few .... We also make them for Caddy when needed... as well as Nailhead