The angle will be important. Did you get a Tiger jib for the project? If yes then you will have a little play as it has 5 clew plate holes that you can attach to. I would try to get as even a pull on both the leech and the foot when I was pulling on the middle of the 5 holes. That way you can adjust up or down while looking at the leech of the sail. If you have a good feeling in your hand you can push the leech and the clew alternately, while sheeted, to see if they have the same pressure. You need to make sure that this is consistant throughout the travel of the jib.

I think that it was recommended that you mount a flat plate on the curved crossbar if you are going to mount the Tiger style traveller. If you do not then the traveller will not be able to swivel and you will be very limited on where you put the sheet on the clew.

Later,
Dan