Applies to 6 cyl and 8 cyl non-supercharged. Cover A90406 with gasket A90383 was painted on the engine.
Working from block outward: Spacer gasket A90381 seals front engine mount spacer A90380. Next A90383 cover gasket and A90406 chain case cover. The A8-403 front crank shaft main seal is a part of A90406 cover, but may be replaced with a modern seal.
Chain case is secured by one SA504 hex bolt marked W or 30, two SN506 flat head slotted screws and two WK5 countersunk shake proof lock washers, ten SA506 hex head cap screws marked W or 30, one NA5 nut, eleven WB5 lock washers