Proper Replacement '72 454 w A/C Fan Clutch

[Owen L.]

Re: Proper Replacement '72 454 w A/C Fan Clutch

What date is stamped on the fan? Those definitely were batch-built, and certainly not every month. I have seen H70 and F71, but have only been paying attention recently.

Here's a photo of the stampings on my fan. I'm thinking A72 is January; my car was built right around May 3rd, 1972 all of the engine casting dates are in the 3rd week of April range.

72 454 wAC 7-blade fan stamping.jpg

[Owen L.]

Re: Proper Replacement '72 454 w A/C Fan Clutch

I decided to buy the Corvette Central repro Switzer fan clutch and keep an eye out for an old unit.

To my great delight, the new one is 0.30" shorter from the hub mounting surface to the fan mounting surface than the old Eaton. This means that in relation to the shroud it fits perfectly. My only concern now is that when I shut off the engine, the new clutch allowed the fan to spin for 3-4 seconds and I'm under the impression that's not good -- could it be that without the hood and not attaining a high engine compartment temperature aren't high enough to have it couple with the hub?