I have been doing some research on the correct water pump for a 69 Hemi. I have looked at the parts books and search on the net.

The consensus is that the 2843290 casting number is the correct pump. The part numbers changed over the years, and I understand the discussion about the 6 versus 8 blade pumps. Unfortunately the casting number is not similar to the part number, and I think because the pump can fit a slew of engines 361 to 426 big blocks, and the fact that water pumps were remanufactured there are a plenty of variations out there.

Here are several picture each with subtle or major deviations between them. Does anyone have a solid lock on what an assembly line version would look like. Some of my examples have internal casting numbers, other don't, one has SO on it, one has round fan mount others are crosses. Even the 2 6 blade fans have difference in the blades. One has a collar other is full and one has slightly taller blades.

The one with the plastic had the 69 part number on a Chrysler box, but the impeller is a Chrysler 59/61 Desoto type impeller. Since the casting could fit any engine I am sure the remanufactures used the best casting they had and rebuilt to the standard of the model they had in demand. I can't see how a 28 series casting number would have been assembly line in 1959, and the same for 1969, when the earlier hemis had a 24 series.

I am looking for confirmation of the correct exterior version for assembly line 69 hemi/big block. Thanks. Pictures attached.

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I believe the flat faced 290 with a 6 blade impeller (similar to the one on the pump with the round fan mount) and a cross shaped fan mount is what you want to go with.

a 1969 426 Hemi would be a 290 casting with a bakelite (plastic) impellar, smaller diameter than the one in the above pic, it was unique to Hemis as the 383-440 did not use the bakelite impellar. The cross type hub is correct on all 383-426-440. The round one is incorrect for all applications.

Interesting, I have never seen the plastic 6 or 8 blade impeller. But what about the actual housing. I show several variations of the 290 above. Which was a 69 hemi? No one will see the impeller and probably not the mount either under the pulley. Though that is easy to change.

The National Hemi Owners Association did a study of Water Pumps and Housing and what parts together cool the best. This was in the 1980s I believe and all the information was put into the New Letter. They found out that the Housing cavitates in the housing behind the pump if the pump and housing are not mated. I believe what was stated is if the pump does not go deep enough to take up the room between the pump and the housing it will cause the cooling system to cavitate and cause it to over heat. There were other things that were found out. Not sure if I still have that News Letter but maybe someone else that belonged back in the 70s and 80s kept the News Letter and can post the information.

I believe the information had nothing to do with OEM casting and part numbers and what was used in each year on the Hemi.

Well, not much really useful info came from this post. Funny how many can tell you something is not right, but can't say what is correct when it comes to variations.

Any way, I have learned a lot talking to a rebuilder and also a parts distributor. These pumps are not hard to rebuild and I do think that almost all of the ones you find on the bay or in junks piles have been rebuilt at one time or another.

As a summary, for the hemi years and about late 68 and up. Hemi and AC cars received the 3.50" 6 blade stamped steel impeller. The pulley ratio was such that hemi cars turned at a 1.2 ratio, and AC cars at a 1.4 ratio. WP turning much faster than motor. Normal cars had a .95 ratio pulley set up. The 8 blade 4.375 impeller is what the normal cars received. You get all this in the service manual.

If you look at the hemi performance documentation from Chrysler, they recommended changing to the smaller impeller. Not for better cooling, but to reduce load on the HP from the WP. Same reason for the thermal fan unit. At higher speeds it reduced load on the motor when the fluid clutch would slip. Yet at idle the higher pulley ratio would push enough fluid for cooling despite the small blade.

Most of the water pumps you will find have an oversized shaft bearing so the hub will stay on after the first rebuild. Crane sell different mechanical seals based on how many times the unit is rebuilt. Sure indicator to tell it has a previous rebuild. Also the OS stamp on the pump casting (Over Sized). Also the 2 piece impeller. The impeller can be pressed on and off a serrated collar that is pressed on the shaft. Made it easier in rebuilding and could save a good impeller.

Here are some pictures of the disassembled pump. Waiting on the new bearing and mechanical seal. You can even get new 6 blade impellers, hubs and the collar device if you need them.

Somewhat correct. I still have that newsletter. They listed casting numbers and part numbers in a chart from '64 to '71. Unfortunately the chart covered everything except the pumps.

Well after all this research on the web and a response from an experienced expert who grades car there still is no real definitive answer. I wonder if there is any real providence on cars to ever really know. Water pump life expectancy was not high and most likely a rebuild by an original owner would have been rare. I have seen quite a few pumps and they all were rebuilds. Also there really is no date codes to help.

Attached are a series of pictures of grouped types. The first type I have found in fewer numbers then the latter. They look more like the early 60s pump 2402291 which had a casting number internally under the impeller. IF you look they have the same outer raised ridge, they have internal casting stamps but now 2843290. They also have tags placed in the mold to have the external casting number present. Some have OS id and some not, and some have Chrysler symbol and some not. Any dates look like casting stuff (shift, day month). To me it looks like the 2402291 mold reworked for the new casting number.

The second type is a different mold in that the casting number now part of the casting with a different style Chrysler symbol. These have no internal markings. The only external markings I have found are stamped "-E-3-, E-5 (twice)" reset no markings. One has no Chrysler symbol cast in, but rather a different style stamp.

Crossed hubs have been 2 styles. Impellers vary significantly from size to one and two piece impellers. Will attach pictures when I can resize them.

I think this is the one off the 68 Hemi

I do not think so. The plastic impeller with metal insert is from earlier cars and some 6 cylinders up to 68. I have this one for a Desoto, but no way a 2843290 casting was original OEM in the early 60s. It was rebuilt to the Desoto spec probably for supply needs. The housing fit I think 57 and up. Just different style casting.

Never had a Desoto and that one has not been rebuilt. I got the short block in 70, two rods out the side of block, that pump was on it but broken like you see. Put it on the shelf, been there ever since. But, hey no problem, it is what it is.
In fact, I still have most of the engine.

Maybe some one took the good pump off and put a bad one on. I have had access to about 40 BB motors in various stages and that have been sitting for years and decades. Some late 70 motor have those pumps on them, and late 60 motor with the newer late 70 style pumps. What ever a person got from the parts counter.

I am basing what I believe from data in the service manuals, and the part numbers for impeller that where listed in the parts manuals. I appreciate the pictures and info.