I'm going to change my flywheel. Ive read on the sr motorsports that they rebalance the counter weight. is this nessisary or are they crazy? RB, mazdaspeed, fidanza etc just use a std part so what is the issue?

next; what seals and bearings should be replaced? the throwout bearing but what other ones and which seals?

is there a need to reface the clutch disk?

 

The standard part will work. It's not necessarilly perfect. There is a tendency for Mazda to use heavier counterweights on the autos for some reason even if the rotors are the same weight; to eliminate resonances peculiar to these cars, who Knows? Someone trying to do it absolutely best as possible might cut it a bit. All of the companies you mentioned have pretty sharp people on staff even if opinions may vary slightly.
Paul.

 

thanks Mazmart

I spoke to a clutch specalist and they said it's best to install a new clutch plate and have the pressure plate machined if nessisary so everything beds in like new.