Propshaft change

[Dan H]

Hi folks

Anyone got any experience in changing the propshaft of an early coupe for a larger centre bearing one from a later model?  I've been told its pretty much a must have if I'm putting in a twin spark.  I assume a bit of modification is required to the mounting points for the centre bearing carrier (and probably nothing else) but if anyone has any hints or experience on what was needed or what has worked, it would be appreciated (upgraded donut, uni as well?)

cheers
Dan