[28chevyguy]

So I need a fan for my 350 in the camaro , everything I find is 5/8 pilot, my water pump is 3/4 shaft.      I was running it around the block figured it wouldn't hurt as long as its movin but yea, it was getting hot , like around 200 maybe , thought the thermostat wasn't opening but the upper hose was hot so that means it was open?  Probably because Im a dummy and theres no fan … didn't realize how hard it would be to find one , I have 2 flex fans here but both 5/8 , anyone got one they want to sell ?

[sammons]

Most the 350 Vettes ran the 3/4" hub hole clutch fans. If you are running or want to run clutch fan, you might be able to get Vette fan clutch. If you are running a non-clutch fan blade, I have used a Uni-step bit and went from 5/8 to 3/4 no problem on a good stock fan blade.

[EDNY]

I know the C3 Corvettes used the larger water pump shaft, I "might" have one from a 79 Vette in my pile...can look tomorrow.

[EDNY]

Sammons and me posted at the same time....consider the cost factor...it might be cheaper to just replace the water pump with the more common 5/8 shaft unit and matching 5/8 fan.  I bet that 98% of the Chevy 350 short shaft water pumps on the parts stores shelves are 5/8" and are a direct bolt in.

[madmike3435]

So I need a fan for my 350 in the camaro , everything I find is 5/8 pilot, my water pump is 3/4 shaft.      I was running it around the block figured it wouldn't hurt as long as its movin but yea, it was getting hot , like around 200 maybe , thought the thermostat wasn't opening but the upper hose was hot so that means it was open?  Probably because Im a dummy and theres no fan … didn't realize how hard it would be to find one , I have 2 flex fans here but both 5/8 , anyone got one they want to sell ?

Those multi hole drill bits that look like a tapered cone.  They can start you off at the 5/8 and mark the drill bit at the 3/4" size, voila its now open to 3/4".  Better choice than using a straight 3/4" drill bit.

DERALE in texas( google them )  also sells thru , CORRECTION.....JEGS various aluminum or steel 6 blade fans that really pull air.  Flex fans belong in the scrap box, do not pull air.

mike............hairball

[madmike3435]

1935 Chevrolet phaeton with 6 blade derale steel fan..........running at 700 rpm idle, try that with a flex fan

mike

[28chevyguy]

Nice, great responces! thanks!    Got my gears turning ,  Sammons got me thinking I might have an aluminum stepper I remember seeing somewhere,, maybe that would bail me out !!

[sammons]

I use the step bits a lot. They work great on plastc lens also, with out cracking. (Installing turn indicator lamps in clusters or blue dots in tail lamps)

[EDNY]

Found one in my "free pile".

[EDNY]

Rockauto has them new for about $21...1979 Corvette, 350 ...just check specs to be sure it has the 3/4 pilot shaft.

[madmike3435]

Found one in my "free pile".

Problem with the clutch fan mechanism is that most of the early cars do not have the room between radiator and engine fan mounting surface to be able to run one. I would have gone the clutch fan route on my 1935 Chevrolets with sbc, just no room.

mike       HAIRBALL

[28chevyguy]

Ok thank you I will look into all of the above im sure I'll figure something out now.