My fan is 16", never had a problem cooling I can pretty much put my hand on the radiator at any given point. If anything it is probably overkill. There are 4 differant radiator options for these trucks I have the largest size available in stock form so that probably helps as well. I have seen much smaller fans set up on some jeeps and other hot rods. A big fairly open grille also helps these trucks cool. The 180 piece is for opening the hood it will eventually have a trunk popper attached in the future hooked up with remote keyless door locks, it is just one of those things that I will complete eventually.
Here is a better look at the fan as you can see it is an 8 blade mounted tight up against the radiator and blows air through very nicely.
1
