Spey RB. 168-25 (Mk 201 Phantom FG.1; Mk 202/203 Phantom FGR.2) 12,250 lb.s.t. dry, 20,515 lb.s.t. reheat
RM JT8D-22 (RM8A AJ-37 14,000 lb.s.t., 26,000 lb.s.t. reheat [RM8B JA-37 16,400 lb.s.t. dry, 28,100 lb.s.t. reheat])
Just a slight difference in thrust there.
An afterburning TF41...