Heater Hose Routing

[L8KRFAN]

The upper heater hose coming from the firewall goes to the water pump but the lower heater hose was capped off by the prev owner and not connected anywhere. Where the heck is it supposed to go? On my 79 Trans Am 403 the lower hose goes to a port on the rear of the intake passenger side. The Esprit 350 has no such port on the intake. Thanks in advance!

[b_hill_86]

My guess is someone removed that port and replaced it with a plug instead.

[Wallington]

The 403 and any F-body with Olds engine, uses a brass limiting valve for that so it's likely original. I'll shoot a pic or diagram later. If it's capped off the other end, a gooday chance it had a leaking heater core and simply bypassed it. Maybe.
Oh wait, are you talking about the 350? What year, engine? Pontiac 350/74?

[L8KRFAN]

The 403 and any F-body with Olds engine, uses a brass limiting valve for that so it's likely original. I'll shoot a pic or diagram later. If it's capped off the other end, a gooday chance it had a leaking heater core and simply bypassed it. Maybe.
Oh wait, are you talking about the 350? What year, engine? Pontiac 350/74?

Yep, 1974 350. I looked and looked and couldn't find anything but will check again. There is a lot of gunk and oil in that area. Thanks!

[L8KRFAN]

After some google searches, looks like there is supposed to be a nipple/port on the very back of the passenger side head which is where the heater hose is supposed to go.

Unfortunately, looks like that port has been capped somehow on my car. Very odd but oh well. It doesn't get that cold here in So Cal so this car will not have heat. Or Air... Or very much else. It's a big-time fixer upper. 

Since that's the case, can I just cap off the port at the water pump? No sense having the hose going from the water pump to the heater if it just dead ends.

[b_hill_86]

Sorry, back of the head is what I meant in my last post. It wasn’t till now that I realize you said on your 403 (which I’m hardly familiar with at all) has a port on the intake on the passenger side. I read that and assumed port on the rear passenger side of the head like the Pontiac’s. I’m a bit sleep deprived with a newborn at home at the moment lol.

You can cap the port at the pump

[Wallington]

This is the 1978 non-AC heater range, all on one page. For 350P refer to 400.

78 Firebird non_AC heater hose routing by Ben, on Flickr

[gstrandfarm9420]

This might be way too late, but in a Pontiac engine there is a press in heater hose nipple in the passenger side head, by the rear of the carb. At least there's supposed to be, its possible someone was swapping heads around and there is just a freeze plug in that spot. The right nipple is available through Ames Performance, an old style  and a new style depending on which heads you have.