does anyone know if the 4dr blazer have speakers in the back doors? my stereo is unhooked and do not know if there is any

 

there are 6 1/2s in the rear.

 

you'll more than likely have to rig up brackets for the speaker ports, if the clips provided with the speaker done work.

my wifes 94, and my friends 93, have the 6.5 in the rear... and the factory speakers are not round, but are oblong in their shape, so the factory holes will never aline right with aftermarket speakers.