Murt,
my assumptions only apply if your water system is otherwise intact and your engine not leaning out or ignition set incorrectly:
I opened my engine bay so that a better amount of air was able to flow through the engine bay. To be correct: I shrouded the radiator only at the sides.
About 15% of the heat will be tranferred via the engine surface (convection).
Heat "loss":
30% = horsepower
30% = radiator
15% = exhaust
15% = engine surface
10% =
oil cooler
Don't nail me down on these %-values.
A bigger fan won't help beyond 30 mph, because than the moving vehicle will pull more volume through the rad than the fan(s).
If the thermostat start the fan(s), that indicates not enough shrouding of the radiator.
I also let the air circulate around the hood. I was too lazy to install rubber here. In addition to that I cut openings into the sides of the hood scoop as seen on the original turbo 427.
I also drive the car without inner fenders which you may not like.
Do not forget to pressurize the system with a radiator cap rated at about 120 kPa or more.
To redefine your radiator's (fan's!) capacity for stop-and-go let the car idle until hot (fan off), cover 30% of the surface covered by the fan and/or place the car in front of a wall and check how the temperature drops. (hopefully!)
As a backup have a water hose handy to spray the radiator (not the engine!) in case your fan can't handle it.
Dave,
I used to tighten the front wheel bearings like this:
turn the nut to the point that you can barely slide the shim with a screwdriver and than find a slot for the cotter pin close by.
Dominik