I am rebuilding a 261 cid engine for my 1950 AD truck. I have been unable to locate the minimum head thickness specification (distance from the valve cover surface to the head surface) for my head. The head casting number is 3836850. My head has been milled, however I do not know how much. If the minimum head thickness value is not available, how much resurfacing is too much? How do I tell how much my existing head has been milled?
Thanks for your assistance, Bill.

check out an older thread entitled "261 torque specs" there was good information given on how to tell if the head had been milled too far. The thread was with in the last 45 days or so. I looked in my 1960 Chevrolet Truck Maintenance manual, which covers the 261 engine and I did not find a spec for head thickness.

The head thickness is probably the same as the 383848 head for the 235. The only major differances are the water jacket holes and the combustion chamber shape. The 850 head has bigger chambers.

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1950 Chevy pickup with '62 261, 4 speed.

Max. removeal would be .060" and anything over about .030" I would start to worry about intake valve to piston clearance, especially with a high lift camshaft. recessing the intake valves is the usual solution, but because of valve geometry and valve spring height, .060" is the limit. Installing shims under the rocker shaft stands when taking off a significant amount is a good idea to help restore rocker arm to valve geometry.
As for a "stock" head thickness, I couldn't say, but I have two heads in the basement that I believe haven't been surfaced, and the hole depth of the front right head bolt is about 3.778" on both, if that helps any.