i have a single 40 on mine, with no tail pipe, just dumps right out after the muffler. i set off car alarms daily. and i have a V6. the reasn the dual is quieter is becuase there is no back compression. thats why im keeping the 2 inch pipe. what i would do is where it goes into the muffler have it tapered to be 2" then either dump it at the muffler or put 2.5" tips on
thats my 2 cents