There is some drilling. You have to drill four holes in your firewall to mount the selenoid. You have to drill a hole in your dash if you use their switch... a shifter switch eliminates that hole.
The wiring is simple, comes with a couple of harnesses that you can tie up under the hood sealing rubber. You have to remove the ECM, but it is easy if you just follow their directions.
There is one vacuum connection you must make, but again, the directions are very easy to follow.
You have to pull part of the harness thru the firewall on the drivers side.
It is only on at idle, and then only when you have it switched on.
Do it yourself... it will be fun and at the same time you will save installation fees. There is a lot of help available on this board.