Engine Indentification Figure 6. Engine Model and Serial Number Location Engine Model Breakdown 934 - DD5 936 - DD8 Engine Certification Label An engine certification label is attached to the engine rocker cover. This label certifies that the engine conforms to federal and state emissions regulations for its application. It gives the operating conditions under which certification was made. The following illustration is a GHG17 engine certification label. 24 All information subject to change without notice. Copyright © 2017 DETROIT DIESEL CORPORATION DDC-SVC-MAN-0192