Good GM heater core info

[Ned Kelly]

Might be a worthy read if you doing a heater core replacement:
http://www.steelsoldiers.com/showth...ent-Heater-Cores-No-or-Low-Heat-Output-Reason

Looks like the Spectra Premium Heater Core 94553 is a good piece to get.

 

[Chevy305]

I recently replaced my heater core with the new aluminum style and was having the exact same problems as described in that thread. I'll definitely have to add some insulation around it to seal it better and force all the air through it. Thanks for the link!