Does an increase in airflow (intake or exhaust runner) move peak torque up or down the RPM band?

greymouser7 said

-So I am going to go with 2 1/2” exhaust with a crossover. Should be plenty and not restrictive. Versus the 2 1/4” I was originally considering(@rumblefish360 ).

If I remember right though, the f bodies usually had a single exhaust and wonder if it will hang low or be very tight around the axle.

I have two pieces of exhaust pipe/w/muffler welded-up that dump before the axle for the initial driving.

Click to expand...

Best to keep the collector diameter to the H (about 20 inches after the individual tubes end) or mufflers.
Power levels your discussing, a muffler with 2.5 inch in/out willgenerally flow with noticibly less restriction at the high rpms than a 2.25.
And muffler is the biggest restriction in the system.
If you want to join into single exhaust, Calvin Elston has done that....
He's been pretty generous in sharing his experiences. Here's one about merging to a single tailpipe.
Flowmaster Outlaw muffler - anti-reversion? - Page 3 - Don Terrill’s Speed-Talk

He has blog, but most of his discussions are on speed-talk, and some on YB.
Exhausting 101

Also, results from open headers vs 2 into 1 near the bottom of this page.
2017: Revisiting 4:2:1 vs 4:1 headers w merge collectors in the modern era - Page 4 - Don Terrill’s Speed-Talk