1994 chevy suburban with 6 speakers

my uncle bought a 94 chevy suburban and we started replacing all the audio, it has 4x6's in the dash, 6.5's in the rear doors and 4x10's in the rear . i got all the 4x6 and 4x10 ran to a 4 channel amp and it sounds wonderful but my question is can  a run them 6.5 to that same amp or should i run another amp. and how does chevy have them wired in from factory to run off the factory deck and brain. thanks

if i recall, the 6.5s in the doors need to be rewired.  there is a factory amp powering them.

The 6.5s in the rear doors are powered by a factory amp. If your 4ch. amp can handle 2 Ohm stereo load, then you can wire the rear speakers to it.Alpine 7903/Kove Aphex Signal Processor/

Streetwires/MTX Blue Thunder Pro 400X5/JL Audio XR570-CXi/Polk Audio DB Tweeters/Image Dynamics IDQ10D4 V.2

factory amp is located under driver's seat. Its a black box labeled active audio in my ride.triedit and gave up