Geno's “boost bolt” does work on all 5. 9 and 6. 7 Cummins engines, but it must be installed in one of the holes closer to the valve cover, not out near the edge of the head/intake cover. Also, it must be used in a position where the intake cover is “thin” enough. The front inner bolt of the 6. 7 liter engine also retains the air intake “horn” so a longer bolt would be needed. Farther back along the head, under the beginning of the cowl overhang, is a suitable bolt. TST also offers a version of a “boost bolt” and theirs has the compression fitting integral with it, needing only the “olive” or sleeve that goes over the plastic line, and the nut. The Geno's version, however, allows you to use a 90 degree fitting if needed for clearance or accessibility. Do not overtighten the boost bolt because it will snap easier than the high strength Cummins bolts.