Spec sheets

[Valkyrie5.7]

The reason you can't find an over the counter dual exhaust is because your engine doesn't make enough power to warrant one. If anything you will lose power with a setup like you described. However, any professional exhaust place can build whatever you wish for on-the-fly so there is no need for detailed measurements beforehand.

To agree with Mike, I'd also like to add that in modern variations of cars like Mustangs (v8 models) and Corvettes that have dual exhaust stock aren't what most people consider a "true" dual. There's a crossover in the pipes and the diameter is generally not huge (2.25-2.5") If you do go with a dual exhaust I would strongly suggest not going over 2.5" pipes with anything like a 305 or 350. You'll never reach power numbers needing more than that without some sort of forced induction or strong h/c/i. I would also suggest having a crossover or you will have a noticeable loss in low end torque.

just my .02

 

[Sideways the Seven]

What is the stock exhaust diameter on an OBS? I'm looking to get a new exhaust made.