There is an article re this on the Club 4AG website in terms of fitting a 7AG - same principle except you aren't changing heads.
You need a bluetop head and a 924 fan belt from memory to make a 7AG. Reports I have read on the web show it is not as brutal as a 4AGZE hence the T50 would hold up marginally better - all depends on your driving habits.
It will sit a lot taller though in the engine bay and if you have a strut brace, you will probably have to remove it.
Also, the engine is torquier but rev's a lot less - I believe the optimal RPM is around 6,500 rpm's as opposed to normal 4AG's which rev higher.