I've done this installation a few times now and I have pics for a write up but never got around to it, yet. The stand height gauge from T&D is used to measure rocker geometry. Basically, the T&D procedure requires you to take a rocker apart and mount the pedestal portion as below:
Then, using the stand height gauge, holding it perpendicular to the pedestal and valve stem will indicate if the geometry is off or not. The T&D kit comes with various-sized washers use to raise the rocker stand, if needed, to achieve proper geometry such as when the rocker stand is too low. In some case, the rocker stand is too high and may require milling the stand bosses on the cylinder.
The normal gauge has a piece of aluminum that runs down the side of the valve stem. I modified the stand height gauge so it can be used with the spring/retainer installed with the valve stem:
There's another way to check for geometry which I learned from Greg Good and is reliable and easier to perform. I'm comfortable doing this procedure now because I've done it so many times. But the procedure requires that you have either the correct length push rod or an adjustable push rod checker set to the correct length and the rocker torqued down with appropriate lash. Essentially, you take a sharpie and mark up the rocker roller tip. Place a piece of tape (optional) on top of the valve stem. Rotate the engine until the rocker goes threw two iterations of movement. This will leave behind a line on the tape/top of valve stem indicating the sweep of the rocker:
If you look at the picture above, the second valve has a mark left behind from this procedure. If the sweep is too wide, or the mark is too high up or too low on the valve stem the geometry is off. It should leave behind a very narrow line a hair before the center of the valve stem.
The rocker stand bolts are the large bolts that sit under the rocker in the pics above. Line up your rocker stand on the cylinder so that the "V10" marking on the stand faces toward you. (that's what I was told but I don't think it matters). Then install the bolts and torque down to 40 ft lbs.
But you need to check for push rod length and find the base circle, or TDC, for the cylinder you're measuring for push rod length. If this isn't done properly everything else will be off.
There's some really good information here by JackB on the topic:
http://forums.viperclub.org/illustrated-upgrades/602295-adjusting-roller-rockers-made-easy.html
I used a 31mm socket on the crank bolt to turn the engine over when finding TDC and adjusting valve lash.
ViperSpecialty, Roe Racing and others sell adjustable pushrod length checkers. I believe T&D also sells it. You can also buy any parts missing from the T&D kit directly from T&D.
Hope this helps.
- tony