I just have a question about line clips. Are the Sig slider type line connectors legal in this event for 60 sized stunt ships? - Thanks.

For FAI: as long as it passes the pull test, it is o.k. to use.

Now a question in return: Are they legal in AMA competition?

There are also failure modes for the Harry Highly mandated "scissors" clips like the clip getting kinked-over and spoiling the line adjustment, then straightening out at a critical time.  They also tend to lose their mojo and let an eyelet slip free.

We are way past due to bury the "scissors" clip rule which was no more than a self-serving business deal by man who wormed himself on the contest board.

Let the pull test speak for itself. 

Furthermore, why mandate the style of clips when the new issue is what kind of knots to tie on fish line?