Mk patrol heater leaks coolant

Hi guys, I was wondering if you could help me out with some advice on the heater on my '86 l28 MK patrol.
A couple of months back I was driving around and suddenly coolant and steam start pissing into the interior of the car! Not just a little bit either. Drenched the carpet and the interior stunk. I got home and realised the head gasket had blown, ended up taking the head off and getting it refurbished.
The engine is running fine and I've bypassed the water line into the heater for now, but i'm not sure which part of the heater to replace, or the whole thing.
Has anyone on here had a similar experience? Is it worth fumbling around fixing it or should i just go to the wreckers and get one? Thanks in advance!

G'day mate, I don't know about the MK in particular, but if you already have the heater bypassed, I would take it out and get a rediator shop to have a look at it. your blown head gasket, heater leak and overkeating are all a bit chicken and egg as to what caused what. Might find that you only have an hose blown of in the heater or a joint leaking. If it is the radiator in the heater box, well your half way to replacveing it anyway.

Being an older model the heater core may be full of mud,
well worth removing and taking it to a radiator place to test and inspect