I have used this company a couple times with great results:

Jackson Speaker Service
3921 Pine Crest Ct, Jackson, MI 49203
Phone: (517) 789-6400

Thru facebook: https://www.facebook.com/pages/Jackson-Speaker-Service/136380446410496

70 Road Runner 383-4 4 speed FJ5 & black guts
70 Charger R/T 440-4 4 speed FJ5 & white guts