Thanks. I forgot to mention that I've checked Crutchfield. They say that 6.5" or 6.75" speakers will fit in the doors and 4x10" will fit in the rear roof. Are those measurements correct? If they are, which door speaker will fit w/o modding the door?
Those measurements are correct, and either of the door sizes they recommend should work fine in the front doors. Especially if you get the adapters that they recommend which have multiple bolt patterns.
The rear doors are really more set up for 6.75" in my opinion. You could do 6.5"s back there, but you might have to drill holes. I used 6.75"s back there and they fit like a glove, even re-used the factory pressure fasteners.
The rear roof speakers are 4X10s. Be wary though, even some 4X10s will need a little work with a grinder to make them fit in the hole. Seems that the ACDelco ones were a little different shape than most aftermarket options. However, I can say that in my experience Kicker KS series 4X10s will fit just fine with no modification necessary.
In fact I recommend Kicker's KS series highly for a nice budget speaker option across the board. That's what I'm using in my Suburban all around. Nice rubber surrounds so they'll last a while, good signal response and THD ratings, and nice silk dome tweeters. If you want to go all out and spend a ton of money look at Focal's Power series, but the Kicker KS would be plenty for most people.
EDIT - Whatever you do, don't buy from Crutchfield if you can help it. They're a great place to shop but they're overpriced as hell. Get the model numbers for what you want and plug them into Amazon.
