While chatting with 70_F100 today about his C6 to T19 transmission swap, I took some measurements of the transmission tunnel cover hole where the T18/NP435 shifters pass through. The cover that I measured came in my 1972 F250 4x2 T18/360, 8,100lb GVW truck.
I heard from 70_F100 that the covers with the hole pre-made aren't always easy to find or inexpensive, and it's feasible to take a cover from a truck that originally came with a C6 and cut the hole in it as needed.
Since I'd already taken these measurements, I figured I'd share them here in case anybody else wants to cut a 4 speed hole in their C6 cover!
To reduce the potential for ambiguity regarding the method I used to take these measurements, I took some photos. You can click on any of these photos to see high definition and resolution editions!
As you can see, whenever it made sense to do so I pressed the transmission cover's flat sides and front squarely up against the face of a wood block; it seemed like the only feasible way to get measurements accurate to perhaps 1/32" or better.
The opening itself measured 5" by 6", or perhaps 6 and 1/32" (as you know, the sheet metal isn't perfectly regular, to say nothing of my crude measuring tools and skills)!
The distance between the left edge and the hole was 3 and 1/8". I took this measurement at several spots along the inner edge of the hole to ensure its reasonable accuracy, and it measured 3 and 1/8" every time.
The distance between the right edge of the tray and that edge of the hole measured 4 and 5/16". On some portions of the hole's inner edge, it appeared to be closer to 4 and 9/32" (1/32" less).
I measured 1 and 7/8" between the fore edge of the pan and the fore hole edge.
And I measured 7 and 7/8" between the fore pan edge and the aft hole edge.
I hope these measurements prove useful to members doing this swap in the future!
Robroy
