Flathead Waterpump Pulleys, wide and narrow, interchangable??

I have been told that the pulleys just press on and off, I need waterpumps with narrow pulley but a pump with the tabs for motormounts and they are all wide. Do they press of and interchange?

 

I don't think that they will interchange. I believe the end of the shaft housing has a different shape.
You can go to VanPelts web site for pics or go to the Ford Barn forum and post there if you don't an answer here.

 

Thanks. I am looking at a pair for sale here and was told by seller they will easily swap out, but I'd like a second opinion!

 

JFYI, all narrow belt pumps had offset pulleys that ran two belts. Ford never used one narrow belt to run both pumps.
1950-'51 Mercurys used staggered narrow belt pumps, similar to '48-'52 trucks, but with the mount "ears" cast higher and about one inch wider.

 

Thanks. V8 bob. Does that mean they do not interchange?

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I had exactly the problem (I think) you are describing. I wanted the 8RT truck pmps with the side mount to use on a '53 Merc Flathead to bolt into my '47 Ford ch***is.

The stock Merc pumps have such a side mount, but the arm is at a different height and on Mercs there are spacers used under the arm to reach the crossmember. I did not want to do that.

I bought new 8RT pumps and press off the pullies from the used Merc pumps and put them on the 8RT pumps.

NOW: a word of caution here.........the pullies are cast iron, kind of bell shaped and will not take much press pressure before breaking. Fortunately, I discovered that removbing and 8RT pulley I didn't need anyway. So I made a fixture to support the pully hub from the underside. I took a piece of pipe, maybe an 1 1/4" or 1 1/2", about and 1 1/2" long (all dimensions are approximate...this was 3 to 4 years ago) and split it lengthwise (saw). I put the pieces around the pump shaft on the backside of the pulley and used a hose clamp to hold the halves together. I now had a good support for the pulley, pushing against the inner hub instead of the outer sheave.

Removed all pullies that way and then pressed on the narrow sheave pullies to the 8RT pumps. Did encounter one unexpected problem. One of the pump shaft/pulley press fit was insufficient. Either the shaft dia. or pulley bore was off a little. Had my buddy bore the pulley on his lathe and make a press in bushing bored to be a tight press fit to the shaft. If not for that, the whole process was really pretty quick and easy.

Ray