Howdy, I have a 1993 k2500, 6.5l Turbo Diesel. Until recently it had a 4l80 transmission in it, but I lost reverse and overdrive was getting to be useless. It is an old farm rig so it is not worth putting a ton of money into. So i got a TH400 from an old military rig and put it in. After cutting and welding the shift arm at the transmission (just turned the dog leg about 180 to get it to reach right), adding flexible lines to match up the oil cooler lines, shortening the front drive line (th400 is about an inch shorter than the 4l80) and moving the support for the transfer case forward about an inch, I am finally to the point of dealing with the vacuum modulator. I do not have a vacuum pump since my turbo has a spring driven waste gate, so I added a line form the air intake ahead of the turbo and ran it to the modulator. I assume this would work for the shift vacuum but would love some input. Is there anything I am missing? Are there any other modifications I should make before hitting hiway speeds? So far I have only driven in 1st and reverse a few feet just to make sure it was working.