Diesel Bombers - Shifting Problem? Cab Floors?

Gentlemen:

I just acquired a 1985 Ford F350 Crewcab (Dually) 4x4 with the 6.9/c6 engine combo for my landscape company. The engine is strong (merely 180k), the frame is solid, its paid for, and I dont care if it gets scratched....

It does shift rather awkwardly though. Now the guy I bought this from told me it had a bad vacuum modulator to the tranny. I bought a new one, and when I went to install it, I removed the hose and found that I had no vacuum anyway...I traced the line and it is broken off on this 2 port vacuum "thingie" attached to the driver side of the fuel injector/timing mechanism doohickey. I apologize for the technical terms- I am new to Diesels.

Here are my questions:

1. What is that "thingie" really called? So I can get a new one.

2. How the heck do you remove it? Is it a small part that comes off the top? or do you need the whole thing?

3. I have experience and knowhow to do most things, more or less whatever my back lets me get away with, but this is my first Diesel. If I pull that off, are a pant load of springs and retainers gonna fall out?

My buddy says it shifts fine, and he is more familiar with diesels then I am, yet it does need to redline to shift- and that doesn't seem right to me. Besides, the modulator was rusted over and there was no vacuum...that must be causing something.

I purchased this thing to be my heavy tow vehicle/second truck. But quite frankly, I have fallen in love with it. I have so far changed all the fluids and filters, new windshield (old one had a bullet hole), six new tires, 4 new shocks, new master cylinder/brake lines/brakes, new front rack-less the pitman arm.

I also found two mouse nests inside the cab, So I ripped out all the carpet, seats, interior moulding, and washed the metal interior of the cab with some Mr. Clean. I removed the upholstery from the seats and threw them in the wash. The smell of urine is now gone. On this subject, I have corrosion (I can see the street) under the drivers floor board, at the base of the doors, and at the rear corners of the crew cab. Based on what's available from JC Whitney, these are typical areas of corrosion in Fords. Are these parts worth getting? They seem pretty cheap...are there other solutions? I would like to make the cab "water tight" before I put it into service.

The shifting issue is the primary concern. I tow some heavy stuff, plus I would like to put a plow on this beast, and start getting a return on my investment.

Let me hear your thoughts gentlemen....or your ridicule. :-)