"Ex-Amtrak AEM-7 937 K5LA manifold repair. Remove stuck hex socket pipe plug in base (which for additional fun has a stripped-out head) and the remains of two 3/8-16 bolts after someone made an attempt to drill them out but the drill wandered and left a significant amount of the old bolt. First I removed the remains, then set up on the mill to install helicoils at the proper bolt spacing 2.750."
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