I JUST assembled my parts yesterday on my car. There's a little bit of trial and error to it, and you'll need a second person to slide the steering shaft in the car while you're under it guiding it. You could almost get away with cutting off an additional .5 inches to ONE end of the splined shaft, because with the angle of everything, it sorta yanks the firewall dust boot over, and stretches it, causing a gap to occur in the foam, and in my opinion, get water in there. I think another half inch (maybe more, would have to have several shafts to attempt this) would bring the angle of the stub shaft, and flaming river joint more towards the center and ease the stress on the firewall boot.
When assembling, I measured my steering rack to find it's "center" and then slipped the coupler over it, and loosened the setscrews all the way out, slid the coupler down as far as I could go, also keeping the splined shaft set screws loose in the coupler. This will let the flaming river joint and splined shaft push further down on the rack stub, and then, I also loosened the set screws holding the splined shaft to the flaming river joint because once you get the breakaway shaft reconnected w/ the steering column you'll play hell trying to get everything together without taking something loose (make sure your column is straight and locked). You'll need to also put the assembled shaft thru the firewall first before attempting to reconnect it to the column's u-joint under the dash. You also dont want any excess spline or stub shaft poking in to the swivel area of the flaming river joint... that will keep it from fully articulating if it runs in to the ends. You'll see what I'm talking about if you play w/ the stuff just mocking it up.
One mistake I made, which I was able to work out, was I went off pictures, and that is hard to do. I pre-drilled all my dimpled holes and pre-cut all my parts, which, ultimately were a little off. I forgot that Jeremi's thread where he showed this in great detail, was for a car w/ the K member spaced down like 5/8 of an inch for the blower! So in reality you could get away with drilling the holes further toward the middle of the splined shaft, and cut just a touch more off the ends. Which, will bring the angle more back straight and, ease the firewall boot stress. I MAY go back and redrill some holes and cut more off the shaft, but I'm fighting my Turbo Chuck motor mounts right now.
I cut down my hollow shaft significantly, and I also cut down the breakaway shaft, because I was literally bottoming out inside the hollow shaft. I cut about 2.5 inches off the breakaway shaft, and well, the hollow shaft, I'm not sure, but it still comes pretty close to the break away joint.
I also learned that when you hammer these parts together... they'll mushroom the ends and not fit together anymore. Whoops. Keep a file on hand. Because if you have to do any sort of trial and error research w/ the stuff... you'll be hammering.
I wish I would have took pictures of what I did, but I was too focused on getting it together. I'll snap pics next time I'm down there working on my car.
DieselDan, I sent you a friend request on FB, I was in need of some assistance since you have installed Chucks mounts already... I need to pick your brain.