Some help greatly appreciated. What size steerer would I need to have on some Project 2 threaded forks, the frame has a 130mm head tube, I'm planning on using a Chris King threaded headset.
yup. The CK 2Nut 1 1/8" has 38.5mm stack height and the GripNut needs a minimum of 34mm steerer tube. Add those numbers to the 130mm and you have the minimum steerer tube length you need. If you want to run a brake cable hanger on the steerer tube add another 5-7mm. In that case you'll need the CK 2Nut. If you want to use spacers add those too.