K right now i bought this car with the engine w/ shorty headers running threw a non-mandrel bent 2" y-pipe. And on top of that its running into a half filled converter which is half melted on the inside. from the converter back has a 2.5" cat but the muffler has a hole in it. So, if i was to run 2.5" or 2.25" duals what u think the gains would be hp wise. Significant?

 

anyone?

 

was the old y-pipe 2 2" into x" or 2 x" into 2"? have you researched dual exhaust? anyway, it depends on what the engine is like, but you should have signifigant gains in hp with a free-flowing exhaust setup.