The TTIs aren't equal-length primaries, but they average right about 32", which is what Hooker advertises the primaries length of the 5209 Super Comps. Both are 2" tubes with 3.5" collector diameters and the effective collector lengths without bolt-on extensions are very close, too.

Neither is an "ideal" design, but the last dyno results using another set of the same model Hookers correlated well to the in-car results with the TTIs. I believe the Hookers are a good alternative for dyno testing when the TTIs don't fit the dyno setup.