Correct Water Pump

Larry, yes I agree the fan is pretty weird looking. I bet he can find one here. A ton of big cars came with one. I have taken 4-5 off cars myself. The one I have was an NOS that was scratched so I painted it. I’ll probably hang on to it.

 

Anyone want some real entertainment just try and decipher that fan clutch chart on the assembly manual page I posted. Funny how after just a few years all those numbers were superseded to just one part number.

 

72 Skylark, I've for the exact same set up in my 71, and the long pump puts the fan entirely in the shroud. It hasnt bothered me because the car cools very well, but by all accounts it shouldnt ..I've also been puzzled because the same set up in my 73 puts the fan exactly where it's supposed to be. Both shrouds are 4.5 inches deep, both cars have 777/778 pulleys, long pumps and short fan clutches. the only variable is my 71 has a 70 radiator support in it, but even when it had a 70 shroud the fan was fully covered. I suppose I could fix this with all the 70 short pump brackets and pulleys, but didnt all 71's and 72's with or without A/C come with long pumps straight from the factory?

 

71-72 was engineered to have the fan further in the shroud for some reason. You are not alone. It’s correct.

 

There is some strange geometry going on the Larry.

 

For kicks one time I experimented with my 71 Stage-1 on a hot summer day. I tried the 70-7 blade 18” fan in my 71 shroud. The car showed no difference in temperature at all with either fan. None.

 

Pontiac, Cadillac, Olds, and trucks had the 7-blade.

Mine is off a 75 Bonneville

 

I bet they all look different and may have a different pitch

 

Here is a pic of one. They are about 2.5" pitch so they move a ton of air.

 

That should tell you that a larger 20" 7-blade that fits the shroud properly should do pretty well. And that the same size (20) with more blades than 5 will naturally move more air

 

I have TA's 71-72 shroud and their al radiator-you have to use an 18" fan with TA's shroud

 

71-72 shroud used a 20” fan.