McManus is seeking a record fourth victory for an owner in the race with I Am Maximus, and he also has leading hopefuls Iroko and Perceval Legallois.
I Am Maximus would be the first runner to carry top weight to victory since triple winner Red Rum in the 1970s, and only one horse – Tiger Roll in 2019 – has defended their title since then.
Mullins has a strong squad which also includes Nick Rockett and Grangeclare West towards the top of the weights.
Gavin Cromwell is set to run Cheltenham Festival winner Stumptown, Perceval Legallois and 2023 runner-up Vanillier.
The Irish contingent also includes bargain buy Hewick, who cost just £800 and won the King George VI Chase in 2023, plus last year’s third-place finisher and 2021 Cheltenham Gold Cup winner Minella Indo, as well as 2024 Irish Grand National victor Intense Raffles.
Gordon Elliott’s team will be led by Three Card Brag, the mount of Sean Bowen, who is on the verge of becoming British champion jockey despite being allergic to horse hair.
Approximate odds: 9-1 I Am Maximus, Iroko, Stumptown, 10-1 Hewick, Intense Raffles, Vanillier, 12-1 Perceval Legallois, 14-1 Minella Cocooner, 20-1 Bar