Getting to the route and gear beta:
by Russ Walling:
This route and its cousin, Jumar of Flesh, live on the West face of the Foundry. The Foundry is the large blocky formation directly behind the JBMFP boulder across the street from Hidden Valley Campground.
The easiest way to the routes is to go to the JBMFP Boulder and head up and right to a low angle ramp system that appears to cut left back behind the main formation. Follow this up with a bit of scrambling to a pretty good trail, some oak trees, and the West face of the Foundry. The routes are pretty obvious. The Six Pack Crack is the route on the right. Jumar of Flesh is the chimney on the left.
Gear: I took a #6 Wild Country cam, and then some 2.5" to 4" pieces. The belay is on a good ledge and takes cams from 2.5" to 4". The route is only about 45' long so one cord is plenty. Maybe an extendo runner if you are going to lower off and belay at the base.
Additional notes and strategy:
Good route for a cold day. The dark rock will soak up the heat. No big mystery on this one. Crux is low down and involves a couple of grunts and a shimmy. There are face holds on both sides of the crack and hand jams in the back of some less than stellar rock. Watch for how your rope is running if you decide to set up a top rope. Look for the can of Coors that is lodged in the top portion of the crack.