I once made the mistake of trying to fit a set of Doug Thorley headers into by 74 FrankenDuster. After somewhere between 12-15 times installing, removing to make clearance dents and trial fitting again, I got fed up and hacked them apart with a sawzall. I ordered TTI pipes and never regretted it. I had every intention of keeping that car but ended up selling it a few years later.
This time I'm working on a car that I plan to sell. I knew these were cheap headers and expected to have a few adjustments to make. If this were a low budget bracket race car, the money saved on headers would be fine. In truth, even with some additional dents they will still outflow even the best factory iron manifold. If & when I decide to build another A body to keep, I will sell parts, mow lawns, wash cars or have a bake sale to have the $$$ to buy a set of Dougs or TTI pipes.