Tony.. let me know what kit it is.. and I can run it in Rock-Sim for ya... and let you know where the CP will be with 3 or 4 fins... can even do an estamint on the weight with the cluster for CG if you'd like.. if it's not a know'n kit.. Give me dia., lenght, basic dimentions of the fins and that should work for CP.
Clusters are awsome.