Heater Hose Help!

[skink4president]

Got a '73 K-5 with auto and air and ran into an odd issue today. While searching for new heater hose fittings I realized things weren't all kosher. Two questions:

1) Are both the heater hoses 3/4" or is one supposed to be smaller (5/8")?

2) The original shop manual shows several different configurations for routing the heater hoses. As far as I can tell the "upper" hose runs to the radiator (on automatics) and the "lower" hose runs to the intake manifold. Can anyone verify this?

I've had most of the engine compartment apart for the better half of the summer attempting repair the "improvements" the previous owner had made. I'm dying to get this thing back on the road. Please Help!

-B

 

[84k5]

They are different sizes.

 

[skink4president]

Thanks. That's what I thought. There were two 3/4" hoses on the truck when I bought it. Looking at the heater core it's obvious now that the hoses are two different sizes. Are they 3/4" and 5/8"?

Also I just noticed that the connection to the radiator is smaller in diameter than the accompanying heater core outlet on the other end. If I remember correctly the previous owner said he replaced the radiator. I'm fairly certain that a 3/4" outlet flowing into a 1/2" inlet is not correct. Just one more thing to figure out I guess.

I've got a wiffle ball bat waiting for that guy should I ever see him again.