TL, sorry to hear the bad news. With the Harrison you may have to go with VZ cats which are triangular and
just fit up beside the T56. The VE cats are bigger again and not straight through as they are fitted right below the exhaust collector in the Commodore. They have an elbow at one end which makes it very hard to fit under a Cobra.
Here is the underbody of my car with the VZ cats and skinny exhaust fitted last week by Yarra Valley Exhaust. The cats are now the lowest point on the car.
