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OK here's my story, trying to get the ole truck running I needed a radiator and bought a new one. The lower hose had to be switched from driver side to passenger. Found a cast iron passenger side pump housing and swapped it out. Everything installed started engine filled with coolant and once it warmed up coolant started leaking from what appears to be the bottom area of the pump where it mates with the housing. Wasn't sure if it was coming from the weep hole or just a crap job of sealing the pump to the housing so I took it all apart and switched out the pump with one I had laying around. Everything back together again, started engine and added coolant, ran for a while once I noticed steam coming out of the top of the rad I put the cap on and then steam started coming from the overflow outlet which is not connected to anything at this point. Turned off engine and once again a very steady stream of coolant began pouring out from the bottom area of the pump. Took the fan and pulley off, weep area was wet but still not 100% sure if that's where the leak is however it would seem logical. I am thinking perhaps my new thermostat is bad and wondering if I should just take it out and try it again. My temp gauge never registered any reading and I am not sure if it works either at this point. My upper flex hose also has a bit of a crimp in it where it mates with the rad, I was thinking of replacing it as well. I didn't think it would make the engine run hot, but I guess it could have played a part in it. Anyway any ideas would help...

Flush the engine out really good,especially if the truck had sat a long time.Keep flushing it out.Water will run out clear then when you hook everything up and run it and re flush ,more crud comes out.I have a 47 dodge truck that was overheating and that was what was happening.Finally ,after several flushings it stopped over heating.Could be that the water pump is not circulating the coolant properly.Run it a little with the radiator cap off and look and see if the coolant start circulating after it reaches temp 160 or 180 degrees,depending on what the thermostate is designed to open at.Water pumps are cheap-$25. Check the thermostate in a pan with water in the stove to see if the thermostate opens.Get a manual temperature gauge,if you can for your truck.They are reliable,easy to instal,no electrical hook ups.

How far is your fan from the rad cores? Do you
have a fan shroud in place? How many blades
does your fan have? Is the water pump new
or something you had laying around? What
psi rating is your rad cap? Many of these trucks
were originally equipped with a 7psi cap. Have
you installed the upper core support shroud
that rests on the top of the support and lays
over the rad tank? While your engine was
being worked on, did you remove all the old
core plugs and clean the block put really
thoroughly before installing new ones? You
mentioned buying a new rad.... is it spec'd
to be an original equipment replacement rad
or does the core count and dimensions differ?
That kinked hose might have played a part in
your heating issue.... but it doesn't sound like
it could be the entire cause. Did you grab hold
of the upper and lower hoses when the engine
heated up to feel how warm they were in relation
to each other?...... just a few thoughts....
John

The new rad is for a 73 D-100 with a 383 same size rad just differant mounts and hose locations, theres probably and inch and a half gap between fan and rad with no shroud. The fan is if I recall seven blade clutch fan. The upper hose felt like it was full but wasnt really all that hot. The lower hose felt empty with engine off. I have ran the engine before with my old leaking rad and never had these issues. At this point I am going to try replacing upper house and removing thermostat, If that doesnt do the trick I will begin flushing.

sweptlinemike wrote:The new rad is for a 73 D-100 with a 383 same size rad just differant mounts and hose locations,

The 73 never came with a 383. The 383 was replaced by the 360 small block.

sweptlinemike wrote:The new rad is for a 73 D-100 with a 383 same size rad just differant mounts and hose locations, theres probably and inch and a half gap between fan and rad with no shroud. The fan is if I recall seven blade clutch fan. The upper hose felt like it was full but wasnt really all that hot. The lower hose felt empty with engine off. I have ran the engine before with my old leaking rad and never had these issues. At this point I am going to try replacing upper house and removing thermostat, If that doesnt do the trick I will begin flushing.

Throw the thermostat in a pan of
hot water to see if its opening up.
Drill a 1/8" hole in the flange before
putting it back in. It'll help "burp"
the block and rad to push out any air.
Does your lower hose have an
internal coil in it to prevent it
from collapsing?
John

The lower hose is new and does not have the internal coil. Looks like I wont be able to get back at it til after Christmas without getting the wife in an uproar plus its turning cold again. Best bet is to wait until I have plenty of time to troubleshoot without causing any holiday drama.

Sounds like Johns on the right track. I'm seconding the motion of your lower radiator hose collapsing and preventing flow.