Dart/Demon/Duster Exhaust Tips - help!

DARTNUT - The ones pictured above are $125 for a set and these are what I'm finding in Ebay and other sources. I've seen some for less, but discovered they were scratched. They don't give a manufacturer for these, but note they're stainless steel and approx 17" long.
"Can you please clarify what would be considered generic...?" No, $125 won't break the bank, ha... but if it's just for cosmetic appeal, I've currently other uses for that money on the car. Comments..? :-k

ALL - I decided to take a peek this morning and whoa... look at you guys! Thx much for the feedback and opinions. I work in the maintenance & engineering side of commercial aviation, thus tend to overthink everythings by habit, ha...

Technical angle: In aviation, understanding those things that impact airflow "pressure" and "velocity" are crucial. Concerning airflow within a confined space (like inside a jet engine or our exhaust systems): We understand that putting a 12" length of 1.5" ID exh pipe mid-stream in a 2.5" ID full system would be a big restriction in flow (the air slows down to squeeze in there, thus pressure rises = flow resistance). The opposite is true if we did the reverse..ie: 2.5" pipe on a 1.5" system....meaning: In that 2.5" ID section, the pressure would immediately drop, and the flow velocity would jump (more flow)... which also creates a moderate scavenging effect = a tad bit more power.

So knowing this, and looking at the shape of those tips, clearly the pressure pulse will drop when the exh flow enters those tips and the velocity would increase... which would logically increase flow and drop the pressure pulse (deepen the tone). The square tip does very little, but they do look great, ha..

So that's what I was thinking, but then "maybe I'm wrong", thus this query. Ya just never know; maybe there's an old Chrysler Engineer type in FABO and sees my question... wouldn't THAT be cool.

Thanks all. AND DARTNUT, let me know, thx much. ;)