a few questions....grille blocks, temperature sensors...

[dupree]

Ok I am getting ready to try some aero mods on my Subaru.
I have a 1994 Subaru Legacy Wagon ej22 4eat
I am looking at putting a grille block on, I am trying to decide which one is the most productive, the lower or the upper block for this vehicle. I will most likely be putting an air dam on it also. I am thinking about 2 inches, so I am not sure if that will accentuate either an upper or lower block or wont have any effect.
Another question is I want to put a temperature probe under the hood, so I can get a good baseline for under hood temps before I start experimenting with blocking the grilles, just wondered if you had an opinion on a good location for the sensor.
and lastly, I think a kammback visor for the rear of the wagon. I know I have seen others calculate the optimal angle for it to sit, just wondered how I would go about doing this.

Obviously each mod will be a one at a time thing with testing to assert its effectiveness. But I am just trying to get all my ducks in a row.

[dupree]

here are some stock photos of the shape of the car

[deathtrain]

Start with the bigger opening. and watch your engine temp gauge.

[skyking]

I have one of these I use whenever I want a remote temp.
http://www.amazon.com/gp/product/B002B0KVFQ/

[Fat Charlie]

I'd start with the upper because it's a smaller project. The lower and the air dam look like they ought to be one piece extending down from that belt molding, a pretty large bit of work.