Shorty type headers Hedmann 75800

Anyone use these or seen them in person on a car...or, heaven forbid, have dyno numbers with them? Seems too easy to install according to the instructions compared to other headers I have shoehorned into a-bodies.

I read the reviews, seems mixed.

https://www.summitracing.com/parts/hed-78500/overview/year/1972/make/dodge/model/dart

sb