Coolant bypass hose?

[JGC403]

Are there different sizes between 318 and 360? I have an OEM 318 4 barrel manifold and the nipple coming out of the manifold is smaller than the one in the pump.

 

[Bad Sport]

That's because the lines that go to the heater core are two different sizes, one is 1/2" and the other is 5.8".

If you are trying to connect the two, just use a piece of 5/8" and clamp it good 'n' tight on the pump.

 

[JGC403]

No not for the heater. Its that little hose about 5" long that goes from the intake manifold to the water pump.

 

[burdar]

I've never seen them different sizes but that doesn't mean they don't exist. The fitting in the intake is replaceable though. It just unscrews. You can get a replacement in the HELP section at your local parts store.

 

[krazykuda]

There were two different sizes. One for the 60's with the cast iron water pump, and then another for 70 and later with the alumionum water pump

 

[scatpackbee]

You have a mismatch in model year manifold and waterpump. Until 1969 the bypass hose fitting and water pump fitting was 1/2 NPT and in 1970 the bypass hose fittings manifold and water pump went to 3/4 NPT. I suspect your 318 intake manifold is from a 1969 and older, and your water pump is an aluminum 1970 style and newer.

 

[burdar]

I learned something new today!

 

[kt340sport]

You could have the right hose , but the nipple could have been changed. One is #70637 , 1971 TO 1976 V8 ,Dayco, the other is #70468 1963 TO 1969.V8 Dayco.

 

[krazykuda]

They used to offer a tapered hose to go with one mismatch, but not the other.


I'm not sure if they're available today.

 

[fishy68]

They used to offer a tapered hose to go with one mismatch, but not the other.


I'm not sure if they're available today.

Not sure if the tapered hose is still available but I've seen adapter fittings that screw into the manifold that adapt it to the larger size to match the new aluminum pump