GM Crankshaft Balancer Puller Kit and Adapter Set Everything you need to pull harmonic balancers having three tapped holes. The shoulder bolts are designed to prevent them from being installed too deeply, protecting the crank sensor and/or interrupter rings from damage. The spacer adapter gives the puller�s forcing screw something to push against. The kit works on 1990�2002 3300 and 3800 V6 engines. The No. 7911 adapter set consists of the spacer adapter and shoulder bolts only, for use with your No. 518 or No. 6930 flange-type puller. No. 7912 � GM crankshaft balancer puller kit. Includes No. 518 flange-type puller and No. 7911 adapter set.