450 LP Head Repair

The restoration of my 58 450 LP has ground to a halt. After about 10 hours of running around the pasture, my repaired head began blowing coolant out of cyl #4. Thinking it was the gasket, I pulled the head and performed a shade-tree leak test in the shop. I found the water jacket in the head leaking around exhaust valve seat #4. Since the head was off, I took it to an engine shop where they pressure tested the water jacket and found porosity leaks in cyl #2 and 3 intake and exhaust ports. I asked a welding shop about it and they didn't give me a good prognosis on welding the ports with nickel rod. The walls are very thin and I dare not risk a welder blowing a hole in it.

As most know, the LP head is highly sought after by pullers so the supply has pretty much dried up. I don't have enough money to start over on a replacement head and I want to keep it original as I am a purist and don't want to put a gas head on an LP tractor. Does anybody out there have an idea on how I can seal the water jacket without resorting to welding or replacing the head? I already have over $1K in mine (guides, seats, valves, welding repairs). Help. Thanks.

Did you try ceramic seal? This is a bottle of white cream you pour in clear water and run to temp. Drain it out and let it stand to dry. We did valve seats on an old case once and had water in a cyl. The hot rod shop sold us a bottle. Never had another problem.
gary

you will have to send it to a place that welds heads the right waay. i take mine to columbus col-weld in columbus ohio. ask for maynard stump. it will cost you another $500 but that is really your only choice if you want it done right. i tried chapin cylinder head once on a 650 diesel head and had problems.

Try this place it's in Nevada, Iowa. I've heard nothing but good things about them. http://www.midwestcylinderhead.com/