200 tdi expansion tank question

first of all hello 1st post and 2 month into owning a 1990 defender 90 200tdi disco engine. love it.

my question is is there any difference in cooling system pressures between the defender 200tdi and the disco 200tdi? my defender has the original expansion tank on, should i fit a discovery one?

Many thanks, Dan

no difference ,and if there was the cap would make the difference

Ive got a 200TDi conversion and the old 19J tank is still fitted and works fine.