Wondering what preforms gains I could expect going to a bigger exhaust. Currently have a 360, 4bbl, with headers going to a 3" collector. The rest of the exhaust is 2"all the way back..true duals. Would a3 inch or 2.5 do much or leave as is? Thanks
As for what I do, 2-1/2 on a street bound, true driver, stock 360 or up to 450 HP if a turbo or chambered muffler is used. In this power range, as Moparoffical said, this is still small cam territory.
A 3 inch dual exhaust I’ll use for a more powerful set up which would include a larger cam. For the street, for me, this is IMO as opinions vary from person to person, a big street cam is a Hyd. 248* @ .050 or a solid @ 255 @ .050. If you fully take advantage of what the cam has to offer, I believe a 3 inch dual exhaust would be right.
Between the styles of doing a dual exhaust, true duals is fine. A few foot pounds of torque and HP can be found by adding an “H” pipe. And then again but at a much smaller margin with an “X” pipe.
I do “H” pipes because there easy to install or even make on your own. The X pipe is not worth the hassle IMO or cost. But I did do one on the wife’s 360. The sound does change and the higher you go in rpm, the more it shrieks like an angry banshee coming for you with vengeance.