Anyone know if water pump and crank 3 groove pulleys off a 71 Olds 350 are the same as 67 400E 3 groove pulleys? I know the part numbers are 587260 water pump. 384679 crank. Mine were. . . . . . .misplaced by my engine builder. There seems to be some interchangeability on the pulleys so I'm hoping. Going prices?

 

George if you find the #'s for ones you need or that might work, I have several 3 groove available if you need. Both water and crank.

 

water pump pulley is 587260
Crank pulley is 384679


Thanks and boy was that quick.

 

It took a little longer with the sandpaper, but here is what I have. All are 3 groove.
Not sure if this helps or not. Let me know if you can use any, Adam.

 

Adam, Not sure of the interchangeability. Hoping someone knew if the 68-74 pulleys which have numbers and dual letters stamped on them unlike 67 pulleys which seem to only have numbers. The 67 numbers of W/P & Crank 587260 & 384679. The 68-74 W/P & Crank numbers seem to be 409807 & 399404 or 399405 respectively. Are they the same physically but just different numbers due to year made? Never thought I'd lose my originals. Not critical right now but will need them in a month or so. Thanks for going to the trouble to sand them. Did they all have numbers on them? There's some on Ebay ( #141832645302)right now but no numbers. Afraid I'll get them and they'll fit, but the belts will be off. Once again, many thanks


George

 

Big Oops! Ebay number is 331726522244. Sorry! These have no numbers at all. May just go on and buy them and take my chances. Maybe someone will chime in and confirm they are all interchangeable or not.

 

George, don't risk your money on the ebay ones. I've got a couple 1967 425's that I can check the numbers on. If Adam has what you need I could key them out for you guys. If he's lacking some I may have what he's missing. It would be the weekend before I can do this, but if you can wait I think we may be able to come up with what you need.

John

 

George, I found another crank unit, 3 groove. It is a larger diameter than all the other
crank units I have. It is KB S unit. I bet Chris knows what the interchangeability could be possibly. I can see what my 66 vert has on it, maybe... my eyes... Is your application 66-67 with the power steering pump on top like they are? And with A/C?

 

John, Thanks. Bought the Ebay ones just now. I'm in no rush. Once I get these I'll send them on to Cutlassefi for my motor he's doing. At least he'll be able to run it with a water pump. Once the motor is back home I'll install the Alt and P/S and keep my fingers crossed that the belts line up. If they don't then I'll post spec's/difference between 67 and 68-74 pulleys. I have a set on my current 1968 350 that in the car right now, and I'll compare those also.


George

 

Mine is a 67 400E P/S (Drivers side, high), Alt (in center), A/C Passengers side). Sure would simplify this if the builder had sent the originals back on the engine. I'll let everyone know.


George

 

Well, shoot! I wasn't thinking. Chris gave me a copy of his spread sheet a while back. Here's what I'm finding on it.

66-67 V8 w/AC or HDC (exc. A.I.R.) Crank 3 groove JB 389645
66-67 " " " " Power Steering 1 groove JM 384678
66-67 " " " " Water Pump 3 groove JH 3911144

OK, this set is for Power Steering and AC but not California Emissions.

 

George I would be willing to bet the 425 units John has, if it's an A/C unit would be the ticket for the one's you need.

 

I don't know if this helps but this is a 2004 version of Chris' spread sheet:

 

GENERALY speaking pre-68 is incompatible with 68+ and in the 68+ range there are several variations. I believe this split is related to the ps pump difference.

Watch closely the SPACING between aftmost groove and next one fwd. It seems to be wider, like 1/4" flattish area, on the early pulleys, and thin, like as thin as possible, 1/8", on later pulleys.

Then there is the diameter and width issues.

It sounds like you need the JB/JH set, per the Pulley Sets tab, '66 Assembly Manual info.

7.2 x ?? and 6.4 x 2.8" respectively.

Both 3-groove

If stamped ID not present, go by diameter, overall width, groove to groove spacing, etc. For crank pulleys I also tried to note the offset from mounting surface to center of aftmost groove. Column I, "1st G"

 

Holy jose a fat ! Had no idea there were so many subtle differences in the sizes. 425's alone have crank pulleys ranging 6.35", 6.40", 7.20", 7.30". Man o man! I know the crank and water pump pulleys almost touch on the engine. So I may be in for a surprise. I'll try to post where I got my numbers.

 

Something like this Chris? It can be maddening finding matching pulleys at
times, and then to throw in the 3 different length water pumps.
And these are just crank pulleys.

 

http://442restoration.homestead.com/...gine_info.html
Scroll down to the pulleys and belts diagram.
The link above is where I came up with my numbers. This is for a 65 442.




Believe Octania is probably right. Also Chris came up with the same. JB & JH pulleys. Numbers are 389645 & 391114. These seem to be what I need.


I apologize for the confusion that I caused. That picture of the pulleys side by side really brought this into perspective for me, Wow! Wander if wrong size pulleys could cause a lot of the overheating threads that seem to plague especially the BB Oldsmobiles? Under driven water pumps?

 

Definitely was the case with my 403 and the fancy aftermarket under drive pulleys. I must have got lucky and bought a March crank pulley and it matched the water pump pulley. It is under driven but not the ridiculous amount of the generic under drive set I bought.

 

Found a JB pulley and what may be a JH pulley. The pulleys were together in a box but the one has no numbers or letters after bead blasting. I'm keeping my fingers crossed. Thanks to everyone for their help. Also picked up a couple of nice 67 throttle assemblies with working transmission switches in good shape.

 

Without ID stamps, one can only go by measurements. Sometimes I had written on the pulley what it came from, then ascertained its PN and/or Letter code by means of what the PN manual and/or Assembly Manual/PIM said it should be.

As for the various measurements, such as 6.35", 6.40", 7.20", 7.30"... those are probably not DIFFERENT pulleys, but measurement variations due to the use of whatever AMD* handy at the time- tape measure, calipers, etc. If they are within 0.1" that's probably "the same." If they have the same letter ID or PN, they are the same.

I am a fan of using the carefully engineered factory cooling packages. Proper fan, pulleys, and WP. For example- I built the 403 for use in the '85 rustbucket.... had to go thru it 100% due to PO idiocy... went with #6 heads for enough compression to match the cam... Older school pre-computer HEI, modified to make the motor behave well. Overheated severely on first road run, due to vastly incorrect timing settings and curve. Worked that out with help from my friends on the internet, and now with std issue #4 WP and the 307's original pulleys and the 85 442 307's ORIGINAL PUNY RADIATOR, she stays at exactly the proper temperature as established by the thermostat.

Note: a JB pulley is NOT a pulley made out of JB Weld, contrary to popular tale.

*AMD is the TLA for Accurate Measuring Device. TLA of course is Two or Three Letter Acronym.

 

Thanks Octania. Have found you to be a gentleman and a scholar. No drama, just researched facts sound opinions based on your library and life experiences. There are far too few of you. Great bunch, generally speaking, here on Classic Oldsmobile.


George

 

George, I found a JH 391114 3 groove water pump pulley if needed. I believe 66-67 400/425.

 

I have 2 67 442s. One has the 400E and the other has a 71 350 in it. The one with the 350 had power steering, but the one with the 400 didn't. The 350 car became a donor for the 400, so I decided to take the power steering from one and put it in the other. Pump bolted on nicely. I had to use the crank pulley and water pump pulley from the 350. Everything lined up perfectly. I was even able to use the P/S belt from the 350.

No part numbers, just thought I would share a working experience.

Paul

 

Ordered and rec'd Cutlass Assembly Manual. Section 6-1 (V8), Pages 195 - 201 show the pulleys used in different configurations.


The 330/400E with p/s & a/c as options has the following pulleys: p/s 384678 (JM), w/p 391114 (JH), crank 389645 (JB).


Assembly Manual on page 195 list the two letter designations for each pulley # along with number of grooves and diameters. There is even a production drive ratio chart so you get everything spinning correctly (not under or over driven?)


Don't know who Chris is but he was spot on the money. I have acquired the proper pulleys and am now waiting for my motor. I am glad I took Joe's advice and got all three of the manuals he recommended. Hoping for Kingsport this year.


Appreciate all the research, digging up old parts and concern by everyone trying to help me out.


George

 

 

Michael, I probably can but will need more information about what you have/need. I'll send you a private message (PM) with what I need from you to match your setup. John