How many ZL1’s are known to have their numbers matching engines?

[William]

Gets more difficult to answer that question as time goes by.

For purposes of this discussion "original matching numbers engine" is defined as, at minimum, the VIN-stamped cylinder block of the original engine assembly. Components contained within or fastened to said cylinder block may or not be original to it.

Current best educated estimate: 19. There are 6 other engines/chassis that both exist but are not in the possession of the same owner. At least one of those engines is damaged beyond repair.

There are 7 surviving engines original to cars that have not been found or no longer exist. A few restored ZL1s have production engines that originated in other chassis.

Complicating the issue: some ZL1 Camaro cylinder blocks were VIN-stamped on the pad with the engine code. A common racing engine build procedure involves re-machining this area, usually obliterating the stampings.