How many fan blades in thermal fan clutch 79 350

[truckin 79]

I finally got around to changing thermostat out in the 79 truck with a 350 and it seemed to help with low temp in truck. The previous thermostat was a 180 and so the 195 seemed to help. The temp gauge in truck does not seem to move much after swap though, it could be sender. I grounded out wire and gauge needle moved all the way to the right. I have a fixed fan blade on truck now but I am thinking of switching to a thermal fan clutch. I figured with thermal fan clutch it will just freewheel most of the time which could save gas a little and keep truck running in the sweet spot of operating temperature. So can someone tell me how many blades there are on a 79 1/2 ton with a 350. I am just going to pick up fan and clutch at junkyard, it will cost about 20.00

[Dead Parrot]

My 75 350 with auto trans and AC has 7. The other common option is 5. Go for 7 with a standard duty clutch. IMO, a HD clutch locks up at too cool a temp. With a standard clutch, temps stay good even on 105* days running the AC and towing stuff.

Another benefit is no roaring fan noise running down the road.

Don't think there is any difference on the fan/clutches until they switched to the serpentine setups.

Most aftermarket temp senders don't play well with the OEM gauges. There are many threads on the subject.