I know the basics but while installing a TCI reverse manual valve body, the instructions say to do some things that don't really make sense to me. I believe them, I just want to understand what is going on.

http://www.tciauto.com/Products/Instructions/instructions/521000_inst.htm

Here is a link to the instructions. I'm talking about the mods to the intermediate servo. What is going on there and why do I need to do this?

Makes the servo apply with more force and release quicker to match the max line pressure provided by the valve body. On the 2-3 shift, the servo has to release the intermediate band at the same time the direct clutch is applied.. if the band doesn't release fast enough, the trans can bind while shifting. This is multiplied with the higher line pressure provided by the manual valve body. The 3 ground flats is a cheap way to increase the surface area of the apply side of the servo piston to increase it's holding power.

EDIT: P.S. If you have a C5 case the adjustment for the bands is different than in the instructions, as the C5's use a fine pitch adjuster screw.

Thank you very much! I was thinking that the three flats along with removing the o-ring was to let it release faster and plugging the hole was to give more apply force. I do have a C5 case also, but I knew about the different pitches already. Thanks again!

Both mods are to increase apply force. the hole you plug is a case vent. Even though TCI's picture is confusing, you put 3 flats into the small part of the pistion, not the large side as the right hand photo appears to show.

interesting. I didnt do either of those with my Art Carr rev man VB... wonder if i should have...