oil pan and water pump what percent black? zl1

[William]

According to the "Mark IV aluminum case engine painting instructions" the oil pan, air inj brkt, distr clamp, frt cover, clutch fork [exposed part] torsional damper, lifting hook, exh manif, clutch hsng cover [all their spelling] was to be painted with black eng enamel.

How glossy? Hard to say. The Aug '69 Cars test of the #3 ZL-1 Camaro has several good undercarriage photos. In one of them the reflection of the oil pan bolts can be seen on the sides of the pan. The ZL-1 Covette display engine seen in period mags has a fairly shiny water pump. Maybe not full gloss but close.

I'm guessing here but I believe these parts were painted prior to assembly. There would have been quite a bit of time-consuming masking required to do this after assembly. Automotive fasteners are virtually always supplied with some sort of coating so paint wasn't necessary.

Good luck with your project! Careful torquing the mains!