904 slipping from 2nd-3rd (with video)

You would have seen the price tag...lol. The Trans go shift kits usually spec a cupped plug that is drilled with a hole of about 1/8" diameter. they have it placed in the pressure feed to the high gear clutch. It's meant to delay the action of the clutch because the clutch applies faster than the band comes off... Sometimes it takes a little trial and error to get the right timing of the two events.

my B&M shift kit had the same plug and it revved going into third and the manual recommended removing it if this occurred...removed it and the problem was solved