Pulleys, Pulleys, Pulleys???

[tomatocity]

Where am I wrong? Can someone identify the part numbers for me? Does someone have their pulleys easily accessible with the part numbers and possible pictures? Please read on if you can help. Thanks.

I have a short water pump, GM Goodwrench 350 engine on a 1971 2WD frame and 1970 AC cab / front clip.

Upper two pulley set
3995646AH
3927789AG
GM3850680

Lower two pulley set + one pulley set
3911013BW (double)
346290ABGM (single)

Power Steering pulley set
3770509CE
3770509GM
3925537DC

I double checked the part numbers.

I have been trying to get my engine back together so I can get started on the body and interior. Well I am stuck with Pulley Problems.

When I purchased the truck it had a four pulley set on the crank (lower) and a three pulley set on the water pump (upper) and a power steering (PS) pulley that did not line up (too far forward). I followed my own advice and went to a used parts retailer and bought (I thought) the correct pulleys. Let me set this straight, I am not blaming the retailer or anyone else. I bought the pulleys at the Swap Meet at Hot August Nights. He gave me a two pulley set (upper), 3927789AG; a two pulley set (lower), 3911013BW, plus a one pulley set for the power steering, 346290ABGM. I bolt everything together, the upper pulley set wobbles and the power steering does not line up (too far forward). I email the retailer with pictures. He calls me and asks what power steering pulley I have. Answer: I dunno. He informed me I had an I-6 pulley, 3925537DC, which has a flat back side. He sends me a different upper pulley set, GM3850680, and a V8 PS pulley, 3770509GM, that has a concave back. These arrived via UPS in a loose bag and the pulleys were beat-up more than I would like. I tried to install the upper pulley set, GM3850680, and discovered it was very incorrect since the bolt pattern was smaller. I could not remove the I-6 PS pulley, 3925537DC, to install the different V8 pulley, 3770509GM, since I did not have the correct tool. Today I went to the Turlock swap meet and found a Snap-On power steering pulley remover tool ($40). Came home and removed the I-6 PS pulley, 3925537DC, and installed the different V8 PS pulley, 3770509GM. The V8 pulley was wobbly and did not line up (too far towards the engine), darn! I removed that pulley and remembered some pulleys I had from my 62 Impala SS. Sure enough I found the same style V8 PS pulley, 3770509CE, and it was straight though it did not line up (too for towards the engine), darn! So it seems to me I have the incorrect third lower pulley but I am not sure. This is where you come into play. I need your educated advice and any pictures you might have. ANY assistance will be appreciated. Tim

[Longhorn Man]

Wow...I've always read about these issues... never seen it actally happen.
I'd probably say start over by getting everything you need off of a single vehicle... or a couple with the exact same set up.

[gonebad2]

I was able to identify a few of the pulleys you listed. I checked several different GM Chevy master parts catalogs. Here's what I have:
3995646 = 1972 6 Cylinder, Water Pump & Fan
3927789 = Not Listed
3850680 = Not Listed
3911013 = 1968 V-8 327 W/ Power Steering
346290 = Not Listed
3770509 = 1964-1972 V-8, Small Block, All
3925537 = 1968 Passenger, Big Block, 396, Except Special High Perf.

The Chevy Master Parts Catalogs I used go up to 1972. I have a CD Rom that goes up to 1975 but I did'nt get into that one ( or the Buick, Pontiac and Olds parts masters).

So, there could be a few reasons I was unable to locate some of the part numbers.

1) They were produced after 1972
2) They could be for another make, IE: Pontiac, Olds, Buick

Good luck in your search, these short pulleys can be a ***** sometimes. I have given up on stock short water pump pulleys and now use nothing but March billet pulleys and brackets. So I can't send you a pic of a stock setup. It really saves alot of headaches..

GM still carries some short water pump pulleys. You may want to check with them.

Hopefully, another member can identify the pulleys that I could'nt.
FYI...The letters at the end of the part numbers are not published in the GM parts masters..

[tomatocity]

Thanks for spending your time to identify the pulleys. This gets me a little closer. If I had it do do over again I would buy aftermarket or a complete existing set. The complete pulley sets at the wrecking yards are almost always gone or broken up.

Since 'gonebad2' was not able to ID this pulley, 346290, I think I need the correct crank pulley (closest to the radiator) for the power steering. Does anyone have the part number for this single pulley or the three pulley set?

[extd56]

My 72 Chevy truck with a 350 and air conditioning runs a 4 pulley set on the bottom and a 3 pulley at the waterpump. My 70 Chevy truck also runs a 4 pulley on the bottom and a 2 pulley on the water pump. Both setups run the power steering belt on the 4Th pulley closest to the motor. You are welcome to look at them if you are in the neighborhood.

[neonlarry]

Gm used and still uses many different pulley combinations (including seprentine) depending on model and options. Trying to buy them buy the piece is an exercise in futility. The best and IMO the only way to get a matching set is to get them all off of the same vehicle.

[tomatocity]

Thanks extd56. I will try reinstalling the 4-pulley set that came with the truck. If it works I am good to go. BTW, the 4-pulley set weights a bunch since part of it is cast.

Yes I would like to come by one of these days to see your truck. Saturday, on my way back from Pleasanton, I plan on stopping by Kevin's to see your Extended Truck.

Do you and neonlarry ever cross paths? If I remember correctly there are quite a few classic car guys in Vacaville. Used to see them parked for weekend breakfast at the restaurant on the west end of town near I-80.

[extd56]

I have never crossed paths with neon larry, don't know how I could miss him.It seems like there are a lot of the 67-72 trucks here in Vacaville, a lot of them are still working for a living with some contractors too.

[neonlarry]

After reading your post again I got another insight to your problem it might not be the pulleys at all but the PS pump bracket.

[tomatocity]

That was my first thought. I think I have the same bracket that is in the picture extd56 attached. It is cast iron, has two points that the pump attaches to, and tapers to one point that bolts to the block. What other brackets are there? Are there more than one PS pump? Are there any previous pictures of PS pumps and brackets on the Board? Without a search function it is difficult to research what has already been discussed.

[JimKshortstep4x4]

Here is a pic of the power steering bracket, (from the assembly manual). This one has the two piece setup, one cast and one stamped part. There is an older version that is all cast, I believe.

Jim

[tomatocity]

Originally Posted by JimKshortstep4x4

Here is a pic of the power steering bracket, (from the assembly manual). This one has the two piece setup, one cast and one stamped part. There is an older version that is all cast, I believe.

Jim

This looks more like. I just realized I was describing the alternator bracket. Guess I was a bit Dain Bread earlier.

GOOD NEWS! After going through all the different combinations of pulleys I decided to go back to the pulleys that came on the truck except for the power steering pulley. Well it works or at least it looks like they line up. The pulley that came on the truck are:
326304, 3-groove, stamped steel, WP
3923898, 4-groove, cast iron, Crankshaft
3770509, single-groove, stamped steel, PS pump
This leaves one groove unused (I think).

Can someone ID the first two numbers? Thanks.

Now I need to clean, bead blast and paint before installing them. I will need new bolts, washers and WP studs since teh ones on there now are metric.

Sure is nice to get over these unexpected hurdles. Thanks for all of your help.

[JimKshortstep4x4]

Sounds like you have solved your problem. Now that you have done the research and work on pulleys, if the issue comes up again you will have the answers!

Jim

[tomatocity]

Originally Posted by JimKshortstep4x4

Sounds like you have solved your problem. Now that you have done the research and work on pulleys, if the issue comes up again you will have the answers! Jim

Finding a complete set of the correct pulleys would be nice so it could documented in an FAQ.
The 3-groove Upper and 4-groove Lower are definitely not the correct pulleys though hopefully they will work. I have yet to bolt everything together to check for alignment.
The one significant thing I found was the difference in the SB and BB power steering single-groove pulleys. The BB pulley has a flat backside and the SB pulley part number ends in 509.