Your daggerboards are just not as efficient as the Tigers. If you are thinking about putting Tiger boards on and just want to check it out without making a commitment to glassing them in then try using some shims. Imagine if you were making a prototype boat and wanted to make sure the placement of the daggerboard trunks. You would make bigger trunks than nessesary so you could move them around some, for and back as well as rake. Use some delrin 1/4 inch sheets. The bottom one will have to be fit unside the 18's daggerboard trunk with a cutout for the new board. The top can be screwed to the top deck so it can be adjusted. This way you will be able to balance the boat without the commitment to perfect placement the first time.

Later,
Dan