Usage:
3408, 3412 Engines Equipped With Aluminum Spacer Plates
Reference: Guidelines For Reusable Parts, "Spacer Plates For 3400 Family Of Engines", Form SEBF8131.
The aluminum spacer plate on some of the above engines where reworked to provide adequate material around the oil supply holes to the rocker arms for the O-ring seals. The holes, from the bottom side only, were counter bored to accept an aluminum washer. This aluminum washer is not available for parts service. The aluminum washer is to have a press fit into the spacer plate. In some instances, the washers could fall out when overhauling or repairing the engine. If this occurs fabricate new aluminum washers as follows.
Thickness: 3.700 ± 0.025 mm (.1460 ± 0010")
Outside Diameter: 27.100 ± 0.025 mm (1.0670 ± .0010")
Inside Diameter: 9.9 ± 2.5 mm (.39 ± .10")
NOTE: Be sure to thoroughly clean the counter bore in the spacer plate before installing the new fabricated aluminum washer. Do not use adhesive.