Anyone know? I just put a new head unit in and I can hear a little static starting, probably gonna need to buy new ones soon. It's a 1987 Iroc-Z....

 

I had a 1989 RS a few years back, and if it's the same speaker sizes as your '87, then the fronts are 4x6s and the rears are 6x9s.
Hope this helps.

Oh.. and if you're at all interested, I have the stock speakers from my 1989 RS should you be interested in stock replacements. PM me if interested.

 

Yep! 4x6 in the dash and 6x9 in the B pillars. I used Boston 4x6 component plates and Infinity Kappa 6x9s with good results.

 

how hard is it to replace them? if i do replace them im gonna buy some nice ones so i can blast the music.....no amp/subs....just some really good loud speakers

 

Not hard to replace them.
Basically unscrew the old speaker, disconnect the wires.
Then connect the wires to the new speaker, and screw it in place.
Simple as that.