1st hand tips please

I loosely hung the tail pipes on the hangers, slid the mufflers on, trimmed the head pipes.
With everything together, I tack welded everything but the mufflers. Took the entire exhaust off and welded the pipes. The only clamps I used was on the mufflers.

The reason I welded the pipes was because a co-worker installed the same exhaust and only clamped the exhaust, he was getting bad exhaust fumes on his car.