I went through several iterations of engine mount and came to the conclusion that it’s not feasible to keep the standard location for MGB engine mount. It’s occupying space that you need for the exhaust. Therefore, the mount needs to be slightly further forward.
An engine mount always consists of 3 parts - the engine bracket, the rubber mount and the chassis bracket. The chassis bracket was moved to the rear part of the crossmember. There’s plenty of room there to make a ~30 degree platform for the engine mount to bolt on to. The rubber mount is a generic engine mount that I purchase from Car Builder Solutions. The engine side was templated in cardboard first and then cut from 5mm sheet steel, then carefully adjusted and trial-fitted until it was perfect. Remember to get both sides at exactly the same angle with engine aligned centrally.