TA Performance or BHJ
the TA works for either stock crank (external ) or forged crank (internal)as it has a removable weight
the bhj has to be ordered for external or internal and with reluctor ring
technically the stock does not need to be changed to SFI because its not a separate inertia ring balancer so the rule on balancers does not apply , but it is a cast unit and they can fail so its not a bad idea to change it out .
if you race a lot i'd go with the bhj balancer which will help dampen the vibration and should extend the cranks life .
the TA is more like the original but its not a cast piece and is fine but its not a dampner