Complete Manifold-Back Exhaust: Accurate vs TTi

Accurate was using the factory muffler hanger locations. TTI uses seat or safety belt bolt for the muffler hangers - I forget which.
At the tail, TTI uses a factory hanger, and Accurate wasn't always.
Accurate's headpipe flange and gasket fits and seals well.
On my '67 Accurate's d/s headpipe hung a little low. That could be car to car variations.
I tried Accurate's X pipe and was not happy.
With exhaust coming out of the manifolds, increasing the diameter, especially bumping for the X pipe, kills velocity.
They have improved their mufflers since I bought. I did flow test the old ones. Good for 2.25" mufflers. Not as high flowing as 2.5" SuperTurbos.

If you want a real good replica of the original system, try Don's Custom Exhaust in Ohio.