heater issue

I have bought a 1956 chevy with a 1998 5.7 carburetor engine.
The issue that I have is when I got it the heater core and valve was not
hooked up. I discovered after I installed the new heater core and valve it
blew all the coolant on the passenger floor. I soon discovered that the water
has to circulate completely all the time with this motor. I cannot find any way
to do this with out a lot of fittings or crossovers. I cannot find this anywhere.
And the guys from the st. Louis tri 5 club are the biggest jerks that I have
ever encountered. I will be 70 at the end of this year and am on my third
brain tumor. I used to build a lot of these (55,57 & 57) when I was in high
school and for a couple of years after. Drastically need some help to enjoy
this cool patina car.