Our 278mm starts it's life out as an I6 TB converter. We do several durability upgrades with the most important being a rear bearing retainer - this is the most common failure we see in the OE. We also upgrade to a HD clutch lining, TIG welding, and HD impeller hub just to name a few. And another big item is our stall recalibration, raise the flash RPM to 3000-3200 range. Much better performance then the OE I6. Bang for the buck with dependability, I think you will be very happy.
The 278mm is in our HP Series line, entry level performance converter. We do offer a Pro Series line, this upgrades you to a billet front and a custom built stall. But I think that is overkill for what you are looking for in a TBSS.
Chris