Replacing the stock delivery valves in your 12 Valve can substantially increase the low end power and fueling, in turn aiding in turbo spool up. 

The 191's are one stage above the stock 181 delivery valves on the later model 12 valves to aid in fueling larger injectors.Kit comes complete with 6 Delivery Valves, 6 Washers, and 6 Gaskets