Mandrel bending versus regular

FWIW, I had a 2.5" compresion bent system with 50 series flowmaster mufflers. Some of the bends were real bad reducing the cross section by 1/2. I replaced it with a 2.5" mandrel bent sytem with turbo mufflers. By the butt dyno I can't tell any difference.

This is with a built 360 that was making 370hp with the compression bent system.

I was not making the change for power. The pipes were not fit well and the shocks would hit the tail pipes on big bumps and I wanted to tone down the noise hence the turbo mufflers.

The one thing worth noting is the least expensive way to get a new exhaust under your car is one of the kits from Jegs or Summit and they come with mandrel bent pipes. These kits can't be beat for $200.

One other thing, if your system is oversized to what the needs of the engine are compression bending is not going to make a measurable difference.