Water Temp Sending Unit Questions?

Hey guys...I've pretty much finished up doing all the electrical wiring to install my 3 gauges on the A-pilar. I followed the basic directions from srothfuss' install and it looks real clean and solid. Im going to make all the connections to the car tommorrow, but i have a question or two. One of my gauges is a 2 5/8" AM elec. water temp and i recieved a sending unit with the gauge, my question is where does that sending unit go? Do you need to drill and tap a hole in the rad or something or does it replace the stock sensor in the front of the Lower int. man? Secondly i got a mechanical boost gauge and it came with a T-fitting to tie into an existing vac line. Which vac line is the easiest to T into? It seems like the T is designed for a larger vac line than the ones used for EGR and FPR...but its not quite big enough for a Brake Booster line? Also what has anyone done to protect that nylon tubing...that wire loom crap? Any help or experience would be greatly appreciated! thanks!
-Nick

I have always been under the impression that the ECT sensor did more than just run the temp gauge. I thought the computer adjusted timing and whatnot depending on Engine Temp?!?!? IF this were the case wouldnt deactivating the stock sensor and wiring cause issues?! Im all for just tossing that new sending unit in the manifold because its a quick and easy solution but if its going to cause any problems then i would rather mount it in another location. Just so we are talkin bout the same sensor...im refering to the sensor thats on the front left part of the lower intake (if your sitting in the drivers seat)...and it has one single wire sitting on the top of it? Thanks in advance.

Thanks guys...thats kinda what i figured. Dont know what i was thinkin. I appreciate the help!