Heater hose fitting mismatch between engine and car?

I am missing one of the heater hose fittings on my water pump. This is a 71 charger with a 69 440 in it. What makes this an odd pairing is the fitting on the firewall are a 5/8" and a 1/2". It looks like the correct fittings for a 69 engine are 2 5/8" fittings. Is this normally worked around by buying a convertor or is there a fitting that works for this that I just haven't found.


Here is a picture of the water pump with the missing fitting



Here is the firewall with the different sized fittings.

Common hardware store plumbing fittings/reducer bushings/nipples work well but are somewhat unsightly. On the nipple that you slide the heater hose on I smooth the threads to protect the hose & leave a raised edge on the outer end of the nipple to help with hose retention (just like the OE Mopar fittings have)

Get the fittings for '70 up big block motors. Herbs, Mega, etc. all carry them.
The 1/2" fitting has a 1/4 pipe thread so you'll need to use a pipe bushing from that size up to the thead in the water pump housing. IIRC it's 3/8 pipe thread. Home Depot sells them in brass. I got my nipples from Herbs.

http://www.herbsparts.com/proddetail.asp?prod=HNK-2

The longer 5/8" fitting goes in the lower empty hole in your pic. The short 1/2" fitting goes in the hole up top where you have an old 5/8" fitting.

Mancini has them also. Worst case you may need a reducer bushing in the WP housing but that is not very noticeable.

Agreed, the correct nipple is far better & a plumbing reducer bushing as needed

Home Depot also sells these internal pipe wrenches. These are great for pulling and installing the nipples.

This is probally a dumb questions but is there anything special to screwing the fitting in? Any special mopar Gel or so to prevent it from leaking?

If i know i will never take it out, i use red loctite.

They are pipe threads so teflon tape or pipe thread sealant work fine.

It's a pipe thread , it sort of is supposed to self seal , but you can put some type of pipe thread sealant /lube on it and screw it in , then clean off what is exposed before painting.

I bought a fitting that from a member in Maine a few years back that was made to fit the larger hole of the WP housing and go down to the smaller hose size.

I also made one , I found a HELP fitting that was the larger thread , and 5/8 hose but the internal hole was the size of a 1/2" barb,I chucked it in a lathe and turned it down to 1/2" barb size.

I still have it kicking around.

Mega Parts makes an adapter hose nipple to use a 69-down waterpump housing on a 70-up car.Their part# is 132-HC010.Good people to deal with. John.

Any farm/ag/equipment shop should have a good selection of brass fittings and be able to get you a 1/2" barbed hose fitting for 3/8 NPT thread. The Fariview part would be 125-8C if it is indeed a 3/8 thread. That plus a tube of permatex thread sealant and you should be out the door for only a few dollars.

Hit any autoparts store and order 4 seansons pt # 84712
Its the right threads for the pump and the right size the heater hose

problem solved