Got 'er all fixed up! Twas the head gasket, it was extremely deteriorated, must have been original from the factory, surprised it was holding any water at all. Found a super low priced gasket set for the 5R at: Sourcefy dot com , just search for part number: 89-605.
Thanks for the insight! Yes, the OEM 35 year old head gasket was totally trashed, never seen a head gasket so deteriorated. Got it all taken apart.
Ordered new gasket fr ForkliftPartsWorld out of LIttle Rock, AR.
Bad head gasket is usually the cause.