Prop shaft tube installation?

[Kvance]

I am building a JAE 21 FE and i amould the ready to install the prop shaft tube . My question is how close to the coupling should the tube be when installed properly? I am aware the coupling and shaft are suppose to be in line with each other, just not sure how much space is needed between them.

[Doug Smock]

1/4" max will do.

[Kvance]

Thanks Doug !!