I would like to know if anyone could tell me what the speaker sizes that are factory installed in a 87 Custom Cruiser are.
I looked at Crutchfield and they say I have no rear speakers, only dash and door panel speakers.
I agree there are ones in the dash, but I can't find any door units and I know there are rear ones beside the tailgate.
Thanks for the help, I appreciate the help and support that you folks have given to me.

 

They are most likely 4x10s, but could be 6x9s.
They are mounted behind the trim on the back pillars on each side of the tailgate window. At least that is hoy the 86 body manual shows. I can't imagine the 87 is much different. The manual gave no sizes.
Disassembly looks easy by the manual; pop the panels out and see what will fit there. It looks quite confined to me.
The Buick wagons sometimes got the door speakers with the Concert Sound II system, but I never saw factory door speakers on the Olds models (strange).

 

Thanks, Lady & Rob it warmed up enough this afternoon that could pull the trim panels off and the speaker are 4 X 10s. I think you are right the Olds never had door speakers as there is no place for them to mount thats not covered in carpet. Thanks for the help.

 

Glad I could help...
If you measure the diameter of the magnet, I could tell you if you have the "extended range speakers" option. If you have this option and you choose to junk the old speakers, I will consider buying them from you for my '86.

BTW, the door speakers on the Buicks were actually semi-surface mount. With some cutting (), they would fit into the Olds also.