Identify '66 Water Pump Pulley #

[Mark P.]

I have a 3 groove water pump pulley on my 66 L36 with K19 and need to know if this is a service replacement or what it is supposed to fit. The pulley number is 3881869D and a possible P after the D. Mine is a low option car without PS or A/C and I'm trying to see if this pulley will work when I get all of my K19 components together. The front pulley/groove on this pulley is significantly smaller in diameter than the other two.

Thanks for your help while I try to wade through the K19 jungle.

Mark

[Peter L.]

Re: Identify '66 Water Pump Pulley #

Mark - Chevrolet Parts & Accessories Catalog shows the application of the 3881869 PULLEY ASSY, water pump and fan as 66-67 PASS (A.I.R. w/ Air Cond.)(8 cyl)(exc. Sp. H/Per., T.H). Hope the info helps. Pete

[Joe L.]

Re: Identify '66 Water Pump Pulley #

Mark------

It's hard to say it it will work for you. However, as Pete described, it was never originally used for your application. Keep in mind that just because the pulley grooves will line up, that does not mean that all is well. The drive speeds of the various driven components is related to the pulley OD of drive and driven pullies. So, while you may achieve alignment of all pullies and the ability to install belts, it is highly doubtful that the speeds of the driven components will be right.

The pulley originally used for your application was a GM #3765427 which had an OD of 7-1/8". This pulley is reproduced and costs about 100 bucks, or so.

[Mark P.]

Re: Identify '66 Water Pump Pulley #

Joe,

Thanks for the response...Any chance that you could tell me who is reproducing it or who the ultimate vendor is? I generally use Paragon, but many of their parts (including pullies) do not reference the original GM#, and if they list component applications, they generally leave out the A.I.R. applications. I'm happy to pay to get the right one, I just need a part number and/or vendor.

Also, I'm having similar issues with my L36 alternator brace. The one spec'd in the Paragon catalog for an L36 doesn't work if you try to attach it to the stud that comes out of the drivers side of the water pump. It hits against the fan on the alternator. You have to bolt it on higher on the block, but then it doesn't allow the alternator to shift far enough for the belt to tighten properly. The AIM shows that it should attach to the water pump stud. The one for a 327 application actually looks to have the correct curvature to make it past the alternator fan and it also attaches at the water pump stud. Any recommendations?

Thanks again...this information is priceless to me.
Mark

[Joe L.]

Re: Identify '66 Water Pump Pulley #

Mark-----

I believe that Paul Baker of Goat Hill is the reproduction source for this pulley. I don't know if the usual restoration parts sources carry it, though. It's kind of an "oddball" and there probably isn't too much demand for it.

If I were you, I'd check with the major sources first. If they do have it, you're better off getting it from their inventory. If you have to get it from Goat Hill and you're going to be at Carlisle, then call them and ask them to bring one with them so you can purchase it there. Cash-and-carry.

The alternator brace you require was once known as GM #3882812. Unfortunately, part numbers are almost never stamped on these braces, so they're hard to identify. I don't know how closely the available reproduction compares to the originals.