Original production line installed 69 Z28 oil pans are getting tougher to find, lots of later issue pans around, but they have a small size dimple on the front of the pan just behind the front seal. The later pan was availiable under #360450 from GM, but pretty sure it’s discontinued. Corvette L82 pan from 74-77 is the same as 360450. Look on eBay, there are usually the late production pan with the dimple listed, but despite what the ad says they are not correct.
Also FWIW the production line windage trays are different too, with just a round hole where dipstick goes through, 1971 and up have a oblong hole.
The height/depth of the Z28 pan is the same as any SBC pan from 69-77.