Here's my 68 console converted to 4 speed. I am using a hurst competition plus shifter . I've heard that the removeable cardboard piece was only required for access to the inland shifter adjustment bolts. My console looks identical to a 4-speed and only requires changing the front plate to the 4-speed one plus the shifter boot. Prices for actual 4 speed consoles are nuts!! Thats why I converted mine.
Actually the cut-out for the console was not used in 1966 with the Inland, and happened because they were changing to Hurst mechanisms in 1968 that were MUCH larger than the Inland. They made the redesign in 1967 to accomodate the new shifter...
