Dynatech Exhaust - 2011 Mustang Shelby GT500 & 2010 GT PoweCat converter/4 bolt collector adapter for Dynatech LTs 2.75" Pair of 4 bolt flange collector adapters with high-flow Powercat catalytic converters to mate up to Dynatech LTs. Pair of 4 bolt flange collector adapters with high-flow Powercat catalytic converters to mate up to Dynatech LTs. Includes donut gasket set and bolts. 2.75" ID slip fit connection, ideal for mating LTs to factory 2.75" H pipe on 2011+ GT500s and Mustang GT 5.0L (requires cutting stock H pipe behind the factory cats).