72 C-20 Help

[saddletramp]

Morning Guys Ive got a 72 C-20 350 motor id like to run a fan cluch so it will run a little cooler this summer the parts guy at O,rielly,s looked up my truck he said the truck came with a thermal fan cluch from the factory?? is that what i need ? Thanks Saddletramp

[72c20customcamper]

I used a Hayden 2747 when I replaced the original non working unit. He’s just calling it by the technical term . Fan clutch is a thermal clutch

[Steeveedee]

There are some fan clutches that do not have the thermal feature.

A non-thermal fan clutch is nothing more than a thermal fan clutch always partly engaged. It provides adequate cooling when needed, however, it does not save you money by disengaging (operating at a lower RPM) when additional cooling is not needed.

You want a thermal fan clutch.

[Stocker]

^^ What they said. Hayden 2747 is a heavy duty thermal fan clutch made by Four Seasons in Lewisville, Texas. It is a perfect replacement for trucks with factory A/C.
A heavy duty clutch will cool better than a standard duty, and severe duty is overkill for normal use, even in hot climates. You should be running an 18" six-blade or better yet a seven-blade fan.

Differences between standard duty, heavy duty, and severe duty clutches can be seen here: https://www.haydenauto.com/en/produc...-types/thermal

[saddletramp]

Thanks for the answer appreciate ya where can i get the 18inch blade fan the one i have doesn't have the hole in the middle for the cluch fan ? Thanks again Saddletramp

[Stocker]

Summit Racing has a 6-blade https://www.summitracing.com/parts/der-17118

Personally I prefer a 7-blade like my OEM fan. Ah, here we go: https://www.summitracing.com/parts/gmk-4012312681

Or try a junkyard, might get lucky and save some $$ to boot.