Well it ain't yur rad, cuz its showing a 30* drop from top to bottom which should be adequate.
If your 6-blade is the narrow bladed one without the air-foil tips, then throw it away. Go get something with all-steel high attack-angle blades with the anti-vortex tips on the end, and make sure is not off a serpentine, reverse rotation system,lol. In your case I would shop for a 7-blader.
Now you got yurself a freaking fan.
Now the diagnoses can begin.
But if your 6-blader does have a similar hi-attack, etc; then go find a regular 8.5x11 sheet of writing paper. Then put the carb on fast idle around 1800-2200 rpm, then paste that paper onto the condenser, off center. Next; grab a corner and attempt to slide it in any direction except towards the center. If yur fan is working right, that thing should want to tear, if it doesn't flat out shred.
