I am rebuilding my 383 in my 1970 challenger vert with A/C. The previous owner used a lot of aftermarket parts in the restoration.
I am trying to get things somewhat straight.

The aftermarket water pump housing has two 5/8 inch heater hose connectors. I know one should be 1/2 inch. I have the conversion for the 5/8 hole to a 1/2 inch.

1. Which hole gets the 1/2 inch connector on the water pump housing?
2. what size hoses go to the water bypass valve and to the heater core?
3. What is the true routing of the heater hoses?

Thanks,
Smos

I ain't sure if they are 2 different sizes as my BB experience is limited (but I do have a 451 (slowly) coming together ) but the (BB) pump housing nipple higher up on top is the hot water coming out from the eng (which obviously will go to the heater inlet) & the forward (lower) nipple on the pump housing is the pump inlet (coming out from the heater). EDIT if the pump has a 5/8 and a 1/2 nipple(s) then the 5/8 one is the hot coolant out from the eng to the heater inlet & that'd be the one on top rearmost on the housing

The 1/2" (rear) is hot coolant out, the 5/8" (front) is return.

Thanks
I found a hard to read diagram for basic routing and I think it confirms that the front (5/8, now) is out of the water pump and the rear toward the firewall 1/2 now) is in to the water pump.

Anybody have a bypass valve? does it have 1/2 inch connection on both sides? Does the heater core also have a 1/2 inch connection?
Thanks

so there is a 1/2 inch connector on the rear of the water pump housing towards the firewall? The 5/8th inch is towards the radiator?
Thanks

Here's where the confusion starts... And probably why you're ..The A/C water valve has {1} 1/2 inch connection and {3} 5/8 connections...5/8 from engine to valve...5/8 to and from the heater core to the valve...Then 1/2 inch from valve to engine..

Don't mind all the aftermarket goodies..The valve placement and hose routing is correct...The label was to show where a large black strap{marked clip} would be in a factory application...If I remember correctly the hoses would be routed through the large black strap to hold them{could'nt be done in this case}...You can make out the 1/2 inch and 5/8 script on the Mopar hoses..

Another point to make would be the hose shield bracket that would be present on a big block...it fastens to the alt.bracket and keeps the hose from contacting the belts...You can see it in this pic...

Thanks!
Much appreciated. Now it all makes sense.

Looks like a beautiful setup you have under the hood.

Thanks,
makes sense now.
The 1/2 inch connector is on rear of the water pump housing and it eventually connects to the 1/2 inch connector on the bypass valve.

Which then routes from the bypass valve and connects to the left (passenger side), left facing the firewall)? connector at the firewall. (I have a left and right connection on the firewall for the heater core). All though I am not 100 percent sure on that part of the equation to the firewall.
thanks,
Smos

WOW!!!!
very cool.

I do have that link. Great site.

Do the heater hoses cross or do they stay even from the bypass valve to the firewall? I can't see the heater hoses behind the back of the engine.
Thanks

Here's the pic you've been waiting for click on the attachment.. Note the direction of flow...The short answer is the hoses do NOT cross over each other...In the case of the E body coolant enters the left tube, cascades through the heater core then exits the right{passenger}tube...heading to the water valve then back to the engine...

Perfect!
Thanks,