The 5/8 at the thermostat housing is the hot in to the landcruiser the bigger is return back from the heater cores
OK, are saying the hose from the fitting at the intake should run to the heater core fitting, and the hose from the water pump fitting should run to the heater control valve? Just trying to confirm.
SBC Coolant flow and heater hose connection guide - https://flowkoolerwaterpumps.com/blogs/cooling-resources/small-block-chevy-heater-hose-connection One of the diagrams I found that suggests coolant flow through the SBC. Being hot water feeds from intake.....cooler water returns back via water pump fitting.
I'm just trying to confirm I have the connections at the firewall (heater core) correct and the related two hoses are going to the correct fitting on the engine side. I've bleed this "monkey" a few times now (lately) with front of truck elevated. I swapped thermostat yesterday and did the bleed process again, still no effective heat. Truck runs fine, temp range is fine, heater control vale is new and works, I"m bleeding using one of the funnels that mounts to the radiator neck and with heat on and I've let it run for 30 min or so. I fill the truck to capacity and then do the bleed process etc and I do get some air out using this funnel with front of truck elevated. With this thermostat swap the heater performance is now worse which is not good.
Conclusion on my part is (a) I still must have an air pocket in the heater core (b) I potentially have the connections at the heater core wrong (c) I have some type of blockage or restriction at the heater core. From memory I believe both sides of the heater core essentially run 5/8 hose, which is just an observation.
So...since I"m going to have to keep screwing around with it, I want to get the heater hoses correct, then I'm going to use one of those air powered coolant fillers that applies a vacuum to the coolant system and use same device to fill the system.
ON the FJ60 at the firewall, there is (a) heater core pipe for one connection and then (b) connection at heater control valve which feeds the other side of the heater core. My assumption is if I have the heater hoses plumbed wrong at the heater core I'm compounding my problem.