The guys at Finishline are great. They have done all the work to my car. Side note. My car same Dyno made more Boost on a 2.7 pulley and less WHP. 787 @ 13psi boost. Makes me think the 2.8 pulley is best for an unported Roush 2650. I do not see the Boost drop that a 2.7 pulley creates...