83 Celica GT Hatch rear speaker install

My brother has an 83 Celica Hatchback and we need to find some speakers that fit in the rear speaker locations. Some guides say 5 x 7's fit and some say 5¼'s fit, however neither do (we tried) The openings are the size of 5 x 7's, but the mounting tabs dont match up (the celica has one in each corner of the hole and the speaker has 6 in diff locations. Thanks in advance Dwayneas quoted from DMX, "Here comes the BOOM!!!"

According to crutchfield.com 4" speakers will fit. Either a 4" speaker or a 4" component set. Check them out, they have a great customer help center, but their prices are high, so I would personally suggest buying from somewhere else. Good Luck.