Does anyone know what the water pump gasket face to pulley mount measurement should be for a 1970 Cutlass S with A/C? It is 6.00" on my later model G-body. But I have read that it is something like 5.625" for my 1970 A/C application.
Is that right?

 

5.625 is correct for 70 with AC.

Don W

 

Thanks a bunch! Looks like Flowkooler 1776 is the right one. Ordered one just now.

 

Before you bolt it on I would check that your lower radiator hose fits the water pump. From 1970 to 1971 the pumps changed sizes for the lower radiator hose.

Don W

 

Thanks Don, I will check the diameter of the inlet on the pump. I haven't bought new hoses yet, so I will likely be back on here asking what others have done if the inlet is different than that year application.

 

Don is correct that 5.6 is correct for 70 with AC.
But if matching what is correct for the year is not an issue, you can use a 6" pump with a 71 Waterpump pulley. All other 70 pulleys will match.

 

Well, dang, now I am gonna have to check to make sure the previous owner didn't change to a '71 up pulley.

 

Yes, identifying your pulley set is key. The 71 three grove AC pulley is smaller in diameter and .4" deeper than 70. In 71 they used the deeper pulley with a 6" pump on AC cars.

 

Damn, now I want to use the '71 pulley with a 6.00" version of the pump. The smaller diameter will turn it faster. Great for around town lower rpm operation and A/C.

So I just called and cancelled the 5.625" pump and ordered the 6.00" pump. If I have the short pulley, I'll get a hold of the longer and smaller diameter pulley. I think this is better all around.
Thanks Rick and Don!

 

Also note that the radiator lower hose nipple is smaller on the '71-up cars vs the '70-older cars. If you get the wrong water pump, you'll have a heck of a time with the lower hose.

1970-older = 2" water pump and 1.75" radiator
1971-newer = 1.75" water pump and 1.5" radiator

 

Ok, does a '71 radiator fit a '70? If so and the distances are the same, the newer pump with a 1.75" inlet and the radiator with a 1.5" outlet would require a '71 lower hose. Would that work?

Keep in mind I have historically been a Gbod guy with Olds. Always wanted a '70 though...

 

My buddy who sold me the car said that he didn't change the pulley so now I need a '71-up W/P pulley. I'll post that in another thread.

 

Rick and Joe - It might make the search easier to figure out the PN and/or TWO LETTER CODE that should be stamped in that pulley (KO?, KM?, something else?)

'71 PIM (aka Assembly Manual) will have pages (first pages of Section 6 or Section 11) showing the various pulleys, belts, etc used that year on different combos (and maybe different series of cars....abody as well as larger cars). I don't have my '71 manual in front of me right now.

Maybe you all already mentioned this in this thread but I haven't gone back and read everything again to see.

 

Hey Patton, thx for the response. I just want to find a three groove pulley for the water pump that is the correct depth for a 6.00" water pump. Seems the '71-up Cutlass app is a little smaller diameter (desired) so that's what I am looking for.

 

71' three groove for AC is "KO". The one on the right in the picture.
The one on the left is a three groove AC for 70'. The 70 is "KF".

 

Ya, I have the one on the left. Thanks for the illustration Rick!
What's the diameter of them?
And I need one of the ones on the right.

 

A quick measurement diameter,
71 - 5-5/8".
70 - 6-1/8".

 

Awesome, that means 12.2% reduction in diameter. And rotation speed increase.

 

Always measure your Waterpump before installing. I have seen so many with the wrong shafts and dimension.

 

Yes, 70 and 71 are dimensionally the same.

Yes, a 71 radiator (or replacing the radiator nipple) along with a 71 lower hose would work.

 

I will get a radiator and a lower hose for a '71 application. I just need a pulley now.

 

I have a couple somewhere around here.
I'll take a look.

 

Thanks Rick!

 

I found a couple of pulleys for you.
PM me if your still in need.

 

Thanks Rick, I'll PM you my info!

 

Just wanted to close out this thread with a HUGE thanks to Rick, he drove from Orlando an hour to bring me a pulley for the 6" snout water pump. And then tried to refuse money for it!! I really appreciate ya Rick, and it's great to meet a new Olds buddy who doesn't live across the country.

 

That's really nice of Rick, good Karna will follow.