I haven't updated this thread in a while, but I am starting to work on finishing up the 4WD conversion. I plan on taking the van to a good driveline shop in San Diego (MIT Driveline) to install the new tailhousing on the trans and install the xfer case, as well as re-gear my front axle and modify the driveshafts. In preparation for this, I wanted to do some of the smaller jobs, including cutting the floorboard and installing the shifter, as well as shorten the fuel tank. I did have a couple of issues, so hopefully someone else will read this and learn from my mistakes.
1. Shifter install- per Chris' video instructions, I attached the shifter bracket to the transmission and made a duplicate of the bend on the shifter out of a wire hanger so that I could mark where to trim the floorboard from underneath the van. Prior to doing this, I had cut the stock trans crossmember and welded in the 3" spacers that came with the UJoint kit, which effectively lowered the trans by 3". I thought that this would give me the proper height of the tranmission so that the throw of the shifter relative to the floorboard would be correct. However, what I did not realize is that the 4WD tailhousing raises the trans mount 3", effectively bringing it back to approx. stock height. So, the hole that I trimmed in the floorboard was too large for the trim piece and shifter boot that came with the kit.
After calling Chris and figuring out where I screwed up, I just ordered a larger trim/boot from Jegs to cover the larger hole, so no big deal. The take away on this is do not try to install the shifter until the trans is modified and the xfer case is installed. 100% my fault, I just misunderstood the directions.
2. Fuel tank shortening- after I dropped the tank and washed it several times with soap/water, I trimmed the tank using the template with the UJoint kit, and dropped it off to be TIG welded, which all went perfectly. It was suggested to me that I use some sort of coating on the interior of the tank to prevent rust from the new plate- after some research online I went with the KBS Tank Sealer Kit
http://www.kbs-coatings.com/tank-sealers.html. It is a three stage process, and after the second stage (Rust Blast) I noticed some grey flakes coming out of the tank while rinsing- after I drained it and let it dry, I realized that what I thought was just a galvanized tank actually had some sort of OEM coating on the inside. The Rust Blast had stripped away the coating on about 1/2 of the tank, with the rest peeling up in various amounts. I spoke with tech support at KBS, and they told me that I needed to order additional Rust Blast and to keep doing that same treatment over and over until all of the OEM coating is removed.
I don't know if another brand of coating would have been a better choice, or how many times I am going to have to use the Rust Blast to get it all out, or if I should have just not messed with trying to add any coating at all. I guess time will tell.