Thanks for in depth response Gav,
I guess it was a fairly open sort of question. My motor is a pretty mild L24 (it has a crow cam in it, a little head work, standard SU's and ignition). From what i have read headers and a set of triples would help it breathe better throughout the rev range and especially at the top end. It is probably overkill for the motor but apart from the ignition there isnt much else to upgrade.
Right now it is making reasonable power - a bit of a slouch of the line though
hope the carbs tune up well, cheers.