67 or 68 was the year the Feds mandated dual circuit. I've done swaps both w&w/o booster, a C10 booster up til 87 can be used pretty easily by drilling a hole or two. Brian


My \'64\'s in the Gallery
Pictures in my Photobucket
1964 C10 Custom Cab 350/700R4
1964 Suburban 350/700R4
1979 Ford F350 4x4 400/c6