I have a 91 GXE max without the Bose system and are confused about the size of my speakers. I would like to install a new hu (probably the Alpine one that is $270) and replace my stock speakers but I don't know the size speakers I need. I'm pretty sure in the front I could put 4x6in. But the back is where I don't know wether 6x9's fit or 6 1/2in?

 

The fronts are 4x6, but you could make you own mounting plate and fit up to 6.5's up there. The rears are 6.5 (actually, 6 3/4, I think). If you install a new head unit, you will need to perform some surgery on the rear amp wires to get the rear speakers functioning. I know someone used to have directions on a webpage but I don't think they are there anymore. Try using the SEARCH function and looking up amp bypass or something.

good luck

davecmu