They are 6x8's or 5x7's....replace 'em with some good 6x8's. Pioneer's, Kenwood, Cerwin Vega. Rockford Fosgate...magnets are deep and if you are really creative, have a stereo shop fashion you some wood panels, or maybe sheetmetal panels that will accept 6 1/2 round speakers and get component set speakers. That is one of my next projects....sheeesh....now all I need is some cash to get this stuff done.
L8R
Rich