Hi there,
As i understand, there have been two major player types in the sequential tail light scene over the years. The first type to arrive on the scene was the plug and play two light per left/right side sequential system. As we all know, our '71 to '73 rear lights are divided into three separate chambers per side. We all know how they light up, and how the center chamber is reserved only for the reverse or back up light. So the first type, only sequentially operates the inner and outer chambers of each side.
Going back about 8 years ago, i went and bought a set of this type, when they were fairly new on the scene. I still have them installed today, and they have proven to be very reliable, trouble free, and look pretty good when operating. Sorry, no vids to demo them. Back then, i paid around the $350.00 Au mark to buy them in from America. The Scott Drake/ NPD systems use the two chambered set up only.
However, as the years rolled on, along came the Easy Performance brand offering up a breakthrough in design, allowing the three separate chambers to be lit up and put to use with a true thee chambered sequential flash effect, which was a fantastic look. You also get to choose what type of sequential effect you want from several sequential flash patterns. (oh yeah!!!) The reverse light is still used as it's always been of course. I also see that the Vintageleds.com are offering their version now of the three chambered sequential type system, sort of on par with the Easy Performance system.
I wanted to upgrade to the Easy Performance system a few years ago, but realized that to buy it would have ended up costing me around the $500.00 Au plus mark to bring them in from America. Given that i paid out good money for the two chambered type initially, i find it hard to justify spending another $500.00 plus on upgrading to the three chambered type system. Sad, as the three chambered type system is really the best way to go for a knockout effect.
Lastly, as to recommending the three chambered types, sorry i can't give advice there as i have not bought or tried them as yet. Maybe some Forum members could jump in there and give you their feedback if they have bought either brands and tried them out. In my opinion, the Easy Performance brand appears to have a kind of edge over the others as they operate as a decent going company dedicated to providing sequential tail light set ups for most makes of Classic American cars, and the most dynamic products. Anyway ..............................................................
Reference link to a two chambered type system being sold currently here in Oz for a CRAZY price of $515.00 Au. Forget it!
https://www.custommustangs.com.au/1971-1973-mustang-led-sequential-tail-light-kit-ea
Greg.