Waiting for my rebuild kit to arrive in the mail, I am hooking up the linkages to the 5spd I installed last summer on my 81' Rabbit. So it went pretty straight forward until I climbed in the cab and did some shifting. I can find all the gears except 5th :? . Some of the linkages I used were from the 4spd I had before. Maybe it's the base linkage to the shifter?
I did this in one of my older gasser Rabbits.
Push down (like you are going into reverse) and try to get into 5th.
You got some 4 speed parts left and they don't like to play together.
Did you adjust the stop gap again?
I did the 4-5 speed conversion on my rabbit, I hated it.
The stop gap probably needs to be adjusted a bit more.

What pieces did you change?
a good trick i found is to turn the bell crank (called relay lever in the picture above) on the gearbox housing upside down so you swap the long and short sides - this gives you more throw and a tighter feel. you need to twist one end of the short socket ended rod around 180deg, easy to do with a vice and adjustable spanner.
I can't really remember which pieces went to the 4spd or the 5spd. I am going back up to the 80' Rabbit gasser that I got the tranny off of and getting somemore parts. I guess was kind of lazy about this by just leaving the 4spd connections. I am thinking about just getting the whole sheebang.
how would i adjust the stop gap?