Early Seafire MkIIcs had the same engine as the Spitfire MkV, the Merlin 45. The Seafire is strengthened to handle the naval equippment and the arrester hook and catapult gear.
Later Seafire MkIIcs, designated Seafire L.IIc, had the Merlin 32, which provided more power at low level. The Merlin 32 boosted the Seafire L.MkIIc's sea level speed to 316mph and its speed at 6,000ft to 335mph, the take off run was reduced and climbrate improved as well. The Seafire L.MkIIc also had a four bladed propeller, the only single stage Merlin Spitfire/Seafire to do so.
In AH we have the Seafire MkIIc with the Merlin 45. It should perform slightly worse than the Spitfire MkV. I suspect that, like the F4U-1D and F4U-1C, the Seafire MkIIc and Spitfire MkVb have the same FM in AH.