I've only fucked with the tccd50 twice and both times it was people who had slapped it on and couldn't get them to run right so they brought it to me. I never was happy with how they ran so I avoided it for years.
Finally bought another one to try on a ZA (with reeds) thinking that might be better. They are over ported out of the box and are touchy to tune with bad low end so I don't recommend it to beginners... But maybe on the ZA it's better? I dunno there are lots of threads bitching about that kit on here.
I've been installing the airsal 44 as a stock replacement for a few years now, it's almost foolproof to tune, didn't need any case match and has a nice flat stock power band just healthier. I put one full slap-on a ZA and it ran great and ripped until the stock case seals went bad. Now it's on an e50 that I loan out or ride to the farmers market or whatever and I have another one chilling on the shelf for a back up motor.
Weld the hood shut stocker stylin'