Yeah I think Frank is probably right on here. On a 29 you will most likely be over powered with the 155 before it blows out.
For comparison a kite for that size boat built of 3/4oz would be a medium to almost heavy air weight but if the sail is used and old you may want to be gentler. Most light air sails for that size boat ,kites anyway, are .5 to .6 oz.
We use 1.5oz kites on 30' boats I race for heavy air, thats our chicken chute! Carry it up to about 30 TWS, of course AWS is probably 1/2 that as we are doing 15 kts.