Originally Posted by opus99

78X is an additional 20 seats compared to a 4 class 772 actually and they’re configured in exactly the same proportions (and an additional 4 cargo pallets). And seat count for seat count wise the 78X is an another two seats more than the 77W in BAs config

speaking in general terms in BAs fleet the only aircraft bigger than the 78X is the A35K, 77W and A380

if you’re looking only at new generation in production aircraft the only thing bigger than the 78X is the A35K.