68Malibu383

Hi all,
I don't own a Corvette but have a '68 Chevelle (with C5/C6 front brakes, if that helps) and am trying to find info on the 1971 - 1982 Corvette triple groove water pump pulley. I found one made by March (pn: 5052) and visually, it looks like what I need but I don't know if it will line up with my crank pulley (small block with short water pump). I called March and all they could say is that it might work if I wanted to shim pulleys but they could not tell me how the rear two grooves compared with my factory '68 pulley grooves. I don't mind shimming the water pump pulley to make it line up with my crank pulley (if that is what is needed).

What I am trying to do is come up with a better belt situation with my car that is running a type 2 pump and a triple groove water pump pulley would work perfectly (one for alternator, one for A/C and the front-most groove for PS). Photo attached (belt is not currently on the PS pump; alt belt visible).

Can anyone tell me if the '71-'82 Vette triple groove pulley will align with my crank pulley on a '68 Chevelle (Camaro, Nova, etc)? The front-most groove position is irrelevant as I can move the PS pump forward and backward as much as I want.

Thanks for any help.

gkull

C-3 Vettes use a so called short water pump with a 3/4 inch shaft size. So the pump pulley has a bigger center hole than a stock Gen 1 type motor.

Hope this helped!

68Malibu383

Thank you. That would be difficult to modify unless the water pump would fit my application. I think I'd have to buy the parts and test fit.

gbvette62

I can't really say how all of the belts would line up, but the 71-82 water pump pulley is not actually 3 groove, but instead two pulleys, one one groove and one two groove. Also, the power steering wasn't driven off of the water pump pulley. On most Corvettes (and many small block passenger cars), the power steering pump is driven by an add on pulley on the crank.

On 71-82's, the two groove pulley goes on first, then the single groove one goes on top of it. The groove closest to the block gets a belt that runs to the crank pulley, and then to the alternator. The belt on the middle groove goes to the crank pulley, and then up to drive the AC compressor. The outer groove, only drives the A.I.R. (pollution) pump. The add on pulley on the crank, only drives the power steering pump. On cars without the A.I.R. pump, only the two groove water pump pulley was used, and on ones without PS, the crank add on pulley wasn't used.

The only three groove water pump pulley I'm aware of, was one that was used on 71-74 big block Corvettes.

70-82 water pumps and their pulleys, have a 3/4" shaft, and a 3 1/4" bolt circle, while 69 and earlier pumps have a 5/8" shaft and 3" bolt circle.

cv67

On A bodys the PS only wraps around the crank, the small outer groove on the WP is for the smog pump.

carriljc

FYI. Some of my pulley research that I did for my 68 L79. I added a/c and PS and removed AIR pump.

https://www.corvetteforum.com/forums...post1595410814

Tell us what water pump you have on that chevelle.

68Malibu383

Wow, thank you all for the detailed information. I'm running a factory-type short water pump on the Chevelle. Yes, the factory PS pump does run off an add-on crank pulley. I've removed that style pump and replaced with a type II that does not fit in the bracket. The type II is currently mounted to the cylinder head and I was using the same belt on the A/C compressor but lack of wrap and a way too long belt caused slippage at times with the AC on.

Anyway, I don't think the Corvette water pump pulleys would work unless I use the Corvette water pump and no telling if the water pump pulley would then line up with my crank pulley.

So, I think what I may do is buy a Chevelle double groove billet aluminum water pump pulley and a single groove and have a machine shop tig weld them together.

Thanks again for all of your help!