[Chevelle SS 396/375]

I bought a rebuilt 1967 BBC short style water pump dated E 10 7 for my '67 L78 engine build, and I'm having a tough time zeroing in on which fittings to use on the pump for the bypass line (on the top...5/8" NPT) and for the heater hose on the side (3/4" NPT). In the photo I have inserted you can see that for the bypass fitting I have two styles, one has a built-in hex for tightening or removing, the second fitting is more like what came in these pumps originally...smooth with no hex, and it has slots on the end to assist with tightening & removal. But, if you know about these pumps the stock bypass fitting has no features for tightening or removal other than using a clamping style tool to grip the fitting. I often see these pumps with the original fitting still in the bypass opening when the pump has been rebuilt, but most have been removed, leaving it up to the new owner of a restored pump to figure out what fittings to use! There must be a reason for this! My hypothesis is the original style bypass fitting (without the hex or the slots) is hard to find!

Next, we have the heater hose on the side....I have a similar question for this one: Which fitting to use? I am assuming the long 3/4" NPT fitting is the most common. But, I believe there can be a short fitting like what I also show in the pic. I'm leaning toward going with the long fitting on the side mainly because it will push out the end of the heater hose beyond the fuel pump more (so it's a better option for clearance I believe).

I believe the threads are slightly tapered on both of these fittings which helps in making them watertight once installed with Teflon paste or equivalent.

But, I am still stuck on what to do about the by-pass fitting. Does anyone know a shop that rebuilds these pumps? They might be aware of this dilemma and why this fitting is so hard to find.

Thanks for any ideas or advice,

John

 

[vortec710]

Probably this fitting is so hard to find is because it's so hard to remove from the manifold, I cracked my 67 L78 intake by prying against it while trying to remove the alum, intake with sticky intake gaskets on it. The manifold was being taken off to get to some snap rings that had come off the lifters and reinstall them. Possibly try some of the RV suppliers, I found some of them stock some interesting manifold fittings. FWIW.

 

[Chevelle SS 396/375]

Probably this fitting is so hard to find is because it's so hard to remove from the manifold, I cracked my 67 L78 intake by prying against it while trying to remove the alum, intake with sticky intake gaskets on it. The manifold was being taken off to get to some snap rings that had come off the lifters and reinstall them. Possibly try some of the RV suppliers, I found some of them stock some interesting manifold fittings. FWIW.

If you’re talking about the fitting on the alum intake manifold, those fittings come with the manifold (at least mine did). I believe they are pressed in, not threaded. The water pump fitting looks similar but there are threads in the hole. If I could retap the threads I’d use my smooth fitting with the notches for tightening, but tapping cast iron isn’t easy, so I may have to go with the hex fitting as it at least threads part way into the hole.

I wish I knew someone who rebuilds these old water pumps....any clues?

 

[vortec710]

Try Hemmings for water pump rebuilders.

 

[68elky396]

Ron at chevycool.com rebuilt a '68 water pump for me. He did an excellent job and it has been performing great for the last couple of years or so. He is a fair and honest man to do business with.

Steve

 

[Chevelle SS 396/375]

I’m going to try and tap the threads in both holes (bypass & heater). If that goes well I’m good. If anyone sees this and has tapped one of these pumps to cleanup the threads please let me know your experience doing that. I’m ready to paint the pump except for installing these fittings.

Also, I’m still confused about the long vs the short heater hose fitting: which one is normal for a non-A/C car? Short one?