Small block headers: worst to best fitting. List your experience.

I've been installing headers since the 60's.
The 4 yr apprenticeship seemed to be an endless chain of 4 barrel manifolds, 3/4 race cams, headers, and 4:11 gears.
Ive installed most brand headers into most breeds of cars, and an A-Body Dodge is a piece of cake compared to some other vehicles .
The older design, generic cyclone, hedman, blackjack, yada yada design, with tubes below the streering gear were often damaged.
Ground clearance was an issue, especially if the vehicle was lowered.
The modern TTI and Doug's are a very similar block hugger design, better ground clearance, no low hanging tubes, and easy access to spark plugs.
I started installing TTIs in the 90's and they were a great improvement over the earlier design. TTI had some rust issues 2000 ish, and trying to warranty from Canada was absurd.
I changed to Doug's, and have installed prob close to 20 sets.
The early sets needed "adjustment" to a lesser degree than previous designs, and have gotten even better in the last few years.
I won't install any other brand now, no need.
TTI and Doug's are both excellent, I feel the Doug's to be a better quality, and dollar value, - especially when on sale .
Good luck, . - jmo