When I did a 6.1/518 swap, I used a cable style throttle body and got a universal style cable and made my own brackets. I think the cable was actually for a motorcycle.

68 Road Runner, 69 Belvedere, 71 Challenger Vert
340 barracuda, 01 Ram CTD, 95 Ram, 04 Ram, 85 Daytona turbo Z
66 GTO, 06 Magnum RT AWD. 07 Ram CTD, 07 Ram