[67chevemall]

I would take the 4" out seal the box. Make new small boxes for them.
Get a amp for the sub, run the highs off a new poineer deck with a built
in crossover for your sub, and 40x4 for your highs.

This way you only have one amp which is good for your electical,
Deck and crossover are one unit, which make things easy, and reliable.
The sub box is seperate and sealed
You only need two 4" and tweeters but four 4" will work too.
Make sure your wiring is good with a nice fuse at the batt.
Grounds are important as anything.

$0.02