Running with the ignition retarded will also result in an engine running hot. The fuel is ignited later which can burn oil off the cylinder walls increasing increased friction as the fuel/air mix burns in the cylinder volume rather than the combustion chamber but the main effect is that the exhaust gas is still burning when the exhaust valve opens causing the exhaust valve/manifold and cylinder head to heat up. I would start with a initial static timing of 10degree BTDC --- first set the engine to TDC with cylinder no 1 on the compression stroke [check both valves are shut] then remove the distributor from the block- align the rotor arm such that its pointing at the number one timing slot on the distributor body then and this is the bit to watch
orient the distributor body in the middle of its travel range of adjustment before reinserting the distributor shaft to mesh with its drive gears. Once you have done that set the static timing to 10 BTDC with a test light between the distributor/points low tension supply and earth- it will light as the points start to open up. This is on the assumption that the points gap is set correctly of course!! The only way to effectively check this on an old distributor is with a dwell angle meter since shaft wear can effect points clearances and thus ignition timing. E.g too wide gap due to wear means the points start to open more quickly effectively advancing the ignition. You will probably have 2 sets of points on the V8 but think of them a bit like 2 separate 4 cylinder engines to make sense of what is going on.
ps posting at this time after watching the last of the Chilean miners being brought to the surface!