There are several issues with your code:
1) a PCCC encoder (as any digital communication encoder) cannot accept a "sine wave" as its input!
it only accepts discrete information.
In this case it should be numbers {0,1,2,...,X-1} where X is the input alphabet size of your fsm's.
2) The output cardinality of the PCCC is the product of the output cardinalities of the two FSMs that you are using,
so in your case is 2^3 x 2^3 = 64, which is not consistent with the size of the modulation you are using
3) The interleaver length is user-defined and there is no such thing as an appropriate length (the longer the better performance... )
I suggest you look and try to understand the EXAMPLE (aptly named pccc.grc) in the gr-trellis/examples/grc
and let us know if you have any questions on this particular example.
Then you can move on to change it according to your needs.
Achilleas