Blocking off the port on the thrmo housing

[NiftyFifty]

Gents...and maybe ladies

I'm forced today to get my cooling system in order as now that I finally have the truck running I seem to have sprung a pretty good leak, so I have the rad out and repaired, but now that I want to hook up my heater core again I'm a bit lost.

I have the port coming off the water pump, then the one on the back of the head, and also the one that comes off the thermostat housing, but no other port on my water pmp to hook that too as I have seen in past manuals. Is my water pump maybe from a differnt application? I noticed the previous owner just had the thrmo housing port plugged off with a chunk of hose, but is this going to hurt anything if I do the same? I know I need to hook the rear port to my lower core hose, and the water pump to my upper, so the 3rd right now is just a potential leak IMO.

#2 question is my rad cap has no spring, but I'm pretty sure that's the norm for this style of rad..I noticed today that my over flow hose was plugged right off so that may have been what built up all the pressure and cracked the tank....but do I need a new cap?

Any ideas would be appreciated....and I know pics would be easier..but just finished my 2nd application of primer so can't exactly touch anything for awhile.

Thanks

[JBNeal]

the factory cooling system ain't pressurized, so the cap shouldn't have a spring in it.

a water pump without the port for the external bypass elbow on top is for internal bypass engines. The internal bypass head will have a bump on the thermostat end of the casting, whereas the the external bypass head will be squared off on both ends. The internal bypass head will have an opening in that bump that should mate with an opening in the head. The head gasket for the internal bypass head will have a corresponding ear for this passage, whearas the external bypass head gasket has squared off edges.

btw, when I rebuilt the 218 in the '48 back in '96, I didn't realize that I had a 218 from a '53. So I have an internal bypass engine with an external bypass gasket set & housing. Now that I've realized this, I know why I have a seep behind the water pump at the head.