[olddog]

Personally I like the TKO 600 ratios and the OD. Mine has the 0.64 OD, which I would much prefer the 0.82 OD. I plan to get the upgrades put it mine, as it does not like to shift well at high rpm.

It is very nice to have enough gears to keep the engine down around 2000 rpm. At these rpms the wind is louder than the pipes, and you can talk with your passenger. You cannot talk much with the engine up near 3000 rpm, unless you want to loose your voice.

It has a lot to do with what you use the car for. If all it is used for is running on a track and maybe driving to and from, then stay with the top loader. If it is only you in the car, maybe stay with the top loader. If you like cruising with your wife or someone else, then you likely want to talk and that can be difficult over the side pipes.

The engine has a lot to do with what gears you need, as well as where will you be driving. If you do a fair amount of interstate driving, maybe a 6 speed would be nice. If your engine is happy cruising down at 1500 rpm you may not need as many gears, as you have a wider low rpm range you can cruise at.

That's my thoughts.