I have the head off my 70 diesel because of pressure in rad. I pressurized both cylinders and #1 left air into the radiator. Anyhow the head gasket was leaking compression only and the head is grooved and will need resurfaced. Can the injector tubes also allow compression into the cooling system or is the chance of it uncommon? I see no cracks in the head, although I will have it magnafluxed. Since these heads were known for cracking, is there a particular area prone to it. How important is the valve recession? I see none listed in the JD manual I have. The one exhaust valve is pitted but will probably clean up with a good margin yet. Also two different manuals have two different torque specs for the head. One says 205 ft/lbs and the other says 275 ft/lbs. Which is correct? Thanks for you help.