help with C-10 parking brake for Shortbox, smallblock and TH400

[88Stanger]

So, i started with a 1969 C-10 longbox with 350 cu in engine with a TH400. I have since cut down the longbox to a shortbox and rebuilt the 350 and the TH400. upon my process, i have rebuilt it from the ground working my way up and i am now trying to get the E Brake done. LMC and Classic Industries show all the parts needed. Basically there is one main cable from the E Brake in the cab, to the intermediate cable and then each side rear cable to the drum brakes. I tried to buy the intermediate cable and they both have the cable for a shortbox but it states without TH400 and yet i have the TH400. They do not show a single intermediate cable for the shortbox with TH400, any have any help with this?
Thanks in advance