My Mind Train headers (photo above) have the 1-3/4" primary pipes. I like them because the design doesn't come so close to the gas tank heat shield.
I use a set of the stainless steel Stinger exhaust port plates on my 4V Cleveland heads. Raises and flattens the port floor where the gas velocity is low.
The resulting port size matches pretty well to the primary pipe of the headers. I did die grind away some weld boogers to smooth things up.
I have no solid numbers, but it sure seems healthier than with the prior set of Hall headers necked down to 1-5/8" at the collector donut.