I'd recommend getting newer-tech series-circuit RR such as Shindengen SH775 or SH847. They don't run stator @100% fulltime like old shunt-circuit RR. Lots less heat to wear out stator and actual gains some Hp and mileage!

Can get Furukawa wiring-kit from Eastern Beaver.
https://www.easternbeaver.com/Main/Elec__Products/Connectors/R-R_Connectors/r-r_connectors.html

Or connectors from Corsa-technic
https://www.corsa-technic.com/item.php?item_id=600&category_id=101
https://www.corsa-technic.com/item.php?item_id=601&category_id=101