Since I am flying blind here I'll just toss in some possible areas to look into. Maybe something will help:
PCV system: Was anything disturbed? All engines need some sort of crankcase ventilation, and an engine with higher blowby will pressurize the crankcase. If there is NO PCV system or other escape path for crankcase pressure, its possible to blow past a timing cover gasket, a crank snout seal or an oil pan gasket. Full throttle will pressurize the crankcase more.
Oil galley plug below fuel pump: If you pulled the pushrod and pump, maybe the galley plug is loose. As with the PCV situation, a loose plug will not only weep oil, but high CC pressure will FORCE oil out.
Maybe you can put the car up on jackstands and observe it with the engine running, trans in low gear and running at a speedo reading of say...25 mph. This may be enough to "load" the motor enough to recreate the conditions to get a closer look.
Keep us informed.