heater core for 1977 c10

[allan Johnson]

are there good and bad{cheap}heater cores for c10,i bought ine from a guy who changed out the original with a cheap one,he said boy it doesnt give heat loke b4,i only get alittle heat if its over 20 degress above,i can hear the deflector door close,both heater hoses are very hot,i looked up some info and it looks like cheap cores are shorter and need a shim to make the length diff,im wonerding ifthe guy put the thing in wrong,lookin for odeas b4 o have it taken all apart,to old 2 do it have to have it done,thanks fir any ideas!its a non air truck!

 

[75gmck25]

I believe the only choice for heater cores is with or without A/C, and I assume they both work about the same as far as heat delivery. However, the shape of the core and the location of the hose connections appears to be different, so I don't think you can swap one with the other. Did your truck have factory A/C?

Take out the screws that hold the glove compartment door on, and then take out the three screws that hold the vertical plastic plenum piece that is behind the glovebox. Then you can see into the plenum and verify the blend door is moving and making air flow go through the heater core. The adjuster for the door movement is mounted on top of the plenum and its easy to reach. You can also clean out the mouse nests, bolts, matchbooks, pens, and other junk that might have fallen in through the defroster vents.

Bruce

 

[Dave M]

You might want have a flick through this recent thread.

https://www.gmsquarebody.com/threads/heater-core.32379/#post-648427

 

[Bextreme04]

I would say if both hoses are getting hot, you have good coolant flow through the core, but there is no airflow going through it to pull the heat out. If it’s working right the feed will be noticeably hotter than the return. I would check the blend door.

 

[PrairieDrifter]

I found a copper/brass core on summit, just like the old ones are. It fit perfect, just like factory. As said above a/c cores and non a/c cores are different.

He may have said what he said because it's probably an aluminum core. Some people have reported the same thing, and some people have reported the opposite.

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