You will find with the Merc covers 3 different PCV/ Cap configurations.
1. Cap in front , PCV in middle (won't clear my hood)
2. Cap back about 6" , PCV in middle
3. Cap at rear, not sure on PCV
and maybe a 4th. Cap in front, PCV in rear.

Tom

Inliner Member 1716
65 Chevelle Wagon and 41 Hudson Pickup
Information and parts www.12bolt.com