A 350ci with a 2" or 2.25" exhaust will develop more low end torque than with a 2.5" exhaust, a 2.5" exhaust helps develop more horsepower in upper ranges than a 2 or 2.25 exhaust. Most trucks benefit more from torque than horsepower in daily use.
We generally use 2 or 2.25 on stock to mild 350ci, if it's being built to race and heavily modified we then step up to the 2.5" exhaust.
Paul Jr @ GMCPauls
