TF performance goodies

Mark I'm not a 904 guru by any means but it's my understanding that you can identify the low gear set trans. by the sun gear. On a standard ratio the sun gear is the same diameter on both sides. On a low gear trans. it's smaller on back side (less teeth). And as for HD/better parts, there is the 904, the 998, and the 999 trans. which are all based off the original 904 platform but the 998 and 999's have more discs in the clutch packs. You have to be careful mixing parts though as they made several changes throughout the yrs. Mostly in the front pump area. You can upgrade the front clutch pack to more clutch discs pretty easy by using thinner ones from the rear clutch pack. Oh yeah, it's also my understanding that the 999 is the only one with a low gear set. Again, I'm not a 904 guru so take this with a grain of salt. I'd love to learn more about them but information is spotty at best.

Here's a pic of a wide ratio gear set