273 Y-pipe?

On the same subject, I like that the factory tested both a 2 into 1 and a dual pipe exhaust and found that the single worked better overall (maybe slightly less HP at max rpm). Some people jump thru hoops (cutting the crossmember) to change to a dual exhaust today.

It reminds me of the 1970's when the Honda motorcycles came with individual exhaust pipes and companies advertised 4 into 1 exhausts with claimed 25% more horsepower. When Honda started selling them with 4 into 1 exhausts, the same companies started selling individual exhaust retrofits, claiming 25% more horsepower.