I am going to be doing this myself. Currently using an fj80 ebrake handle I cut in on the outboard side of the drivers seat, but it gets in the way pretty bad, so my plan is to reinstall the under dash linkage for the t-handle, then simply splice a cable from the firewall pull to the actual ebrake cable somewhere under the rig. When I installed my narrowed rear housing, I had to use cable clamps to take up the slack on the OEM cable. Given they haven't slacked, or budged in over a decade, I'd have to assume they would work fine as a cable splice...
