Curious mind wants to know...
 

can the wheel tire combo on the full side Cheny trucks fit on a Blazer?

Yeah if you want to convert to 6 lug.

What does this entail? If it is straight forward, what are the advantages and drawbacks?

The drawbacks would be a more exspensive rim, and tire.

Can't really think of the advantages other than looking cool?

what bout older five lug fullsize wheels and tires?

I believe that the older full size 2wd trucks had a 5 on 5" bolt circle. So no dice... 4WD GM trucks were 6 lug going back a LONG way. Only the 2wd trucks were 5 lug and I believe that they were 5x5 for a long time.

A lot of the older GM car rims will be 5x4.75 like the s-series trucks though. I know that the rally's from my '70 Chevelle would have bolted up to my old '00 Bravada.

anything on a 5x4.75 will bolt on. (5 lugs, 4.75 around the lugs (connect the dots))
it's back spacing that becomes an issue. if you want bolt on and go rims, your stockers have 6" of BS so you would want something as close to that as you can get it.
You can work with all of the S series like Kyle said, (blazer, jimmy, bravada, s10, s15, sonoma, etc) plus you can get away with Corvette, Camaro, Nova, Chevelle and El Camino Rims. Search around on here. There is a ton about this very thing.

you COULD get a converter plate to bolt on you your wheels (5x4.75) --> 6 x whatever, but you would be sticking them out further and putting something between your wheels and axels... so give a little (strength and safety) to get a little (new look). worse things have been done though :D