They bolt right up but know that they're not just from older models. In fact, the large black plastic folding mirror that most consider the "new style" actually began in 1992 on the Suburbans etc. as power mirrors. In late 1994 they became common on pickups with up level trim (Silverado) as mostly manual mirrors though some very rare pickups got power mirrors too.
Now back to the "dumbo ears" steel mirrors like you're asking about, they continued to be used all throughout the GMT400 family, just far less common on the newer trucks. The RPO code for the stainless dumbo is D45, "mirror o/s (outside) - lh & rh wide load stainless steel" - the painted black ones are D44.
Richard