Michael and William Dunlop will face strong opposition from visiting stars Guy Martin and Dan Kneen at this weekend's Armoy road races.
The Dunlop brothers both won two races apiece last year but Manxman Kneen has been on a hot streak of form at the Irish national road races this season.
William and Guy Martin will ride Tyco TAS Suzukis, with Michael on board his BMW Superstock and Supersport Honda.
Kneen campaigns Suzuki machinery for the Cookstown BE Racing team.
The Braddan man has won the feature events at Cookstown, Tandragee, Kells, Skerries and Walderstown.
Other leading contenders will include Republic of Ireland trio Derek Sheils, Derek McGee and Michael Sweeney, plus Saintfield's Davy Morgan.
Newcomer Danny Webb, comeback man Keith Amor and Connor Behan ride for the KMR Kawasaki team in the Supertwins, with another debutant, James Cowton, also in the field.
Roads close from 12:30 BST to 19:30 on Friday for practice and a Supersport 600cc race,
and then from 10:00 BST on Saturday for an 11-race programme.
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