My 13B Cosmo Hybrid-Turbo Vert is having a rebuild to fix a leaking oil O-ring and its going to have a half-bridgeport done while its appart.

How much retuning of the haltech will likely be required?

 

Completely.

 

Are there tuning MAPs avalable that would likely be a better place to start than the current non-halfie-bridge ones?

I'm running an E8.

 

possibly, that should be left up to whoever is tuning your car.

since your going to re-tune now anyways, this is the time to think about other changes that you might want to make, such as switching to the "low" 0-9000 rpm point. Adjusting injector sizes, fuel pressures or changing the way something is set up such as injector staging from common to primary hold.