[swamp rat]

Originally Posted by badpeanut

Your heater core connections are reversed compared to mine and what is shown here (see automatic trans figure): http://67-72chevytrucks.com/vboard/s...7&postcount=18

+2 I see this a lot too, plus the heater core inlet and outlet are different sizes. So if the core is mounted upside down i imagine it could lead to a problem. Actually that whole thread is worth the read, good info.