Mark VIII wiring idea
 

Just ordered the Mark VIII fan. I tried the Black Magic with the Griffin rad and it will not do, just plain sux.
I was thinking of wiring in two Painless relay kits. The first with the temp sender and the second with the a/c for the high speed. I could also addd a switch into the second relay to turn it on with a switch.

Does this sound like a good idea? From what I understand the Mark VIII fans are two speed right?

Yes they are a 2 speed fan but only if you have the fan control unit that comes with the car when you buy it. The fan by itself is only a single speed. It has a 3 pin connector on it.
One for POS
One for NEG.
The third pin is a signal wire to let the OEM fan control unit know that the fan is working. For us, the third pin is only good for hooking up a little light on the dash so you know it is running.

On a side note:
I hope you have upgraded you Alt. to at least a 130amp. This fan sucks up a lot of juice.

yeah already made that upgrade.
I am hoping this fan keeps the engine cool, as nothing else has worked, not even the aluminum radiator.
So do you think I should go with the temperature relay kit and just add a switch into that to turn it on or off when I want to?

Yeah, just go with a switch to turn it on or off and your temp sensor. I have not had a single problem with heat since I had to wire my fan direct. I used to have a PSM1 temp. control unit but it died.
Be cautious with the Aluminum Radiator as they are thicker then the copper rad. and you will have to cut the shroud a little more to make up for the tickness. Just don't take off too much as the fan blades will attack the radiator and make one hell of a mess.
Not shure where right off hand but there are a few links for pictoral walkthroughs of installing the fan if you searck at google.com.
Which ever car you put it in you will stay cool.

THX