Maybe more trouble than you want but I made a console and dropped a stereo in it with the 5 1/4" speakers. 6x9s went under the package tray. The console is removable and you'd never know it was there.

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‘72 Charger, 5.9 Magnum, Tremec 5 spd., Pro-Touring
‘14 Big Horn, Quad Cab, 4x4, 1500