95 4 door speaker size

ive looked all over the place to find out wut the hell the speaker sizes are for my 95 gmc jimmy its a 4 door and the guy i bought it from blew everyspeaker out cept for the rear right one but i want to put some decent speakers in them anyway anyone know wut size i need to buy??

dash- 4x6
front & rear doors- 6 1/2

thank you