Hey guys looking for an alternative fan thats better then my stock 4 blade on my 283.part numbers if u got them. Its for a lot of cruising and traffic. Also would like to run it with a thermo clutch thanks.
Are you having a problem with over heating?
"Normal" temps for cast iron heads, basically stock engine, 180 degree thermostat should stay around 180 degrees with any forward speed around 20 mph (or above); fan has no impact. Sitting at idle in traffic temps may normally rise to 210-215. Not a problem if intermittent and it goes back to 180 when forward speed is resumed. A 50/50 coolant mix at 15 psi boils at about 260 degrees. The 'idiot light' does not illuminate until about 240 degrees.
If you are getting temps above 180 while moving forward, the problem is not the fan. Could be radiator or something else. If you are getting temps above 215 sitting at idle, the first thing to do is make sure your timing is correct. Next, make sure you have a proper shroud and the fan blade is located properly in relation to the shroud (that needs to be done if you change fans too). IF you still have too high temps, six blade fan like this (not the only one):
It will directly replace your 4 blade.
GM provided 4 blade fans for sbc engines under 300 hp, unless they had A/C. The 300 +hp engines, and the ones with a/c, got 5 blade (unsymmetrical) fans and the fan clutch. The fan clutch does not improve cooling. It dis-engages the fan at temps where the fan is not needed. This allows the torque used to turn the fan to be applied else where (propulsion).
As Dave said Hayes sells the clutch(es). You may have difficulty find the GM 5 blade fan. You MAY (emphasis on MAY) have to fork over $$ for what is advertised as 'Corvette' fan (but really isn't).
I ran my '63 Impala's 386 hp "383" sbc with a 4 blade fan for 3 years in N. Virginia. I occasionally got temps as high as 220 sitting in traffic in summer at 90+ degrees outside (NEVER boiled over). Because I was driving in a manner that produced those temps rather frequently, I switched to the 6 blade fan. Nothing over 205 since.
Don't know why you asked, just trying to be helpful.