Speaker size question 98 malibu

So I have a question. The speakers in my car need to be replaced. And I admit with speakers I can be cheap. I would rather find me some used cheap (or free) before I go and buy some. Which brings me to my questions. From what I read the rears are 6x9 and front 4x6 correct? If not what size are they?

Second my mom has a 93 Caravan that she said I could pull the speakers out and use. I believe they are infinity speakers but I am unsure on that. The sizes are: Dash 5 1/4 - Door 5x7 - Rear 6x9....Can I use any of those in my car.

Thanks for any help.

Man, (or woman): PLEASE!!! You can get 6x9s for $9.99 at Wal-Mart with a good quality sound. Why go on the cheap?

Not to be snarky but because I don't wanna pay if I don't have to. These are free if they will work and if I pull them.

But thank you for the advice on whether they would work or not.

Well, they should work if the size is right. You might need a soldering iron and you will need to hook up positive to positive. etc.

I've always made it common practice to avoid clipping factory connectors. Get polarity right and use snipped paper clips to mate the connectors. Then tape/shrink tube the connection. Keeping the connectors provides for the opportunity to return the replacement speakers to the donor vehicle.

-Mark T.