2.5 to 3.0 Exhaust

d1970 said
if he goes to the bigger 3 inch exhaust, he going lose some low torque, that what's get the car moving. Especially with a low compression motor, less back pressure with the 3 inch then 2 1/2.

Back pressure, or the lack off, has absolutely nothing to do with a lack of torque. None would be the goal. This has been proven time and time again.

A properly designed exhaust system can make more power than open headers for street, street/strip cars. Here again, zero back pressure is the goal.