Dynatech Exhaust - 2011 Mustang Shelby GT500 Collector Adapters for Dynatech LTs 2.75" Pair of 4 bolt flange collector adapters to mate up to Dynatech LTs, for off-road use only (no cats). 2.75" ID slip fit connection, ideal for mating LTs to factory 2.75" H pipe on 2011+ GT500s (requires cutting stock H pipe behind the factory cats).