The 235 in our new truck(1948) has a lot of black sludge in the block. I've pulled the drain cock from the block and tried to back flush from there. No luck. I made a plate to go in place of the thermostat housing and tried to flush that direction, without luck.
I've got a new radiator to put in, but need to get the sludge out of the block before I install the radiator.
Does anyone have any ideas short of hot tanking the block?
I'd like to get it running and check it out before tearing into the engine.
Thanks