You need to look where the hot air goes after it comes out the back of the shroud. Some cars it has a tendancy to just cycle back under the front of the car and go back through the radiator. Hot air rises and it will find the easiest way to go up. Look for big holes through the core support. Also look for an air dam under the core support to keep air from "recycleing".

Mabey an easier way to look at it would be too flip the car upside down (in your mind not reality) and pour water in the engine compartment and where it the majority going to go when it starts to get full, would it overflow to the area in front of the radiator?

A easy way to verify this might be the problem is open the hood and see if it still gets hot.

Still wondering what ratio AF to H20.

What pullys are you useing?

Your running problem will still be there after you get the engine to stay at 180-190 unless you keep the fuel from vaporizing where ever it is doing it.

Pusher fans are about worthless.

Also not all recored radiators are the same quality. The savey savoy project had an isue with the radiator cores not being right and causing over heating. Mabey someone can post a linki with pics for you to look at.

How much space is ther from the tip of the blade to the edge of the shroud?

Tons of stuff to try, don't give up! No reason for it to ever heat up if you don't want it to.