My truck got reassembled without the heater box because it was broken. I need to look at removing the lower mounting studs and see whether that is easier than pulling the whole front end.
The large diameter 3/4” hose goes to the water pump with no restriction. The small diameter 5/8” hose goes to the intake manifold with a restriction nipple. If you do it backwards, do a high rpm with the thermostat closed, You will rupture your new heater core!
i hade a car years ago after an engine swap where the intake hose was hooked to the 3/4 tube on the heater core and the water pump to the 5/8, heater worked good, but when in north dakota its was below zero the heater could not keep up. switched hoses around and after that at below zero had to turn heater down
Do you think it was getting air trapped in it and reversing the hoses let the air bleed out properly? I could see that happening with mine since the heater core sits vertical but so far it has always been adequate, although it never gets below zero here
@@PracticallyStock I could have probably worded my comment better as the flow of coolant in and out of the engine to the heater core and the hose sizes. Being all said its hard to say but it made a difference in COLD temps. Also on my old 85 square body coolant flowing out of engine intake is 5/8 to 5/8 end of heater core and coolant flowing back out 3/4 core end to right side of radiator tank. On older GM's I've seen the 3/4 heater core end hook to the water pump.
Aluminum heater cores are a joke put one in my 80 never got warm. Took the old brass one to the radiator shop had it rebuilt. Warm and toasty at 20 below
I didn't notice a difference between the two, I'd bet there was something else going on like it having a 'factory clogged' option lol. I did save the old one though in case I decide to fix it
My truck got reassembled without the heater box because it was broken. I need to look at removing the lower mounting studs and see whether that is easier than pulling the whole front end.
I don't know how they were removed from this truck but I was thankful. From what I saw, the studs seem to make things difficult
The large diameter 3/4” hose goes to the water pump with no restriction.
The small diameter 5/8” hose goes to the intake manifold with a restriction nipple.
If you do it backwards, do a high rpm with the thermostat closed,
You will rupture your new heater core!
i hade a car years ago after an engine swap where the intake hose was hooked to the 3/4 tube on the heater core and the water pump to the 5/8, heater worked good, but when in north dakota its was below zero the heater could not keep up. switched hoses around and after that at below zero had to turn heater down
Do you think it was getting air trapped in it and reversing the hoses let the air bleed out properly? I could see that happening with mine since the heater core sits vertical but so far it has always been adequate, although it never gets below zero here
@@PracticallyStock I could have probably worded my comment better as the flow of coolant in and out of the engine to the heater core and the hose sizes. Being all said its hard to say but it made a difference in COLD temps. Also on my old 85 square body coolant flowing out of engine intake is 5/8 to 5/8 end of heater core and coolant flowing back out 3/4 core end to right side of radiator tank. On older GM's I've seen the 3/4 heater core end hook to the water pump.
Aluminum heater cores are a joke put one in my 80 never got warm. Took the old brass one to the radiator shop had it rebuilt. Warm and toasty at 20 below
I didn't notice a difference between the two, I'd bet there was something else going on like it having a 'factory clogged' option lol. I did save the old one though in case I decide to fix it
Aluminum doesn't hold heat great for radiators not so much heater cores. I put two in both sucked