whilst i am rebuilding this box of bits MC16 is it worth replacing some of the ignition/carbs/exhausts/etc with later model parts to give more power/reliability? i don't want a supertunned racebike that only makes power above 13,000 rpm but if there are upgrades that will give more power without mucking anything up then please do tell.

I only ask cos Andy mentoined that MC21 carbs are a good upgrade and there are some for sale in the classified.
what is a reasonable price to pay??

thx
sfsr