Does anyone know what the size NPT fittings are for this wastegate? I do not want to know about the V-band clamp side, just the spring side. There are locations for four (4) fittings and I believe I need two (2) plugs and two (2) barbed fittings to hook to the manifold and boost controller. They are not a english thread size and must be metric so...what size are they?

 

Actually, they really are English threads on the HKS GT 60mm wastegate

We use National Pipe Thread (NPT) in fractions of an inch and these threads are British Standard Pipe Taper (BSPT) 1/8" 28 threads per inch using the 55 degree Whitworth thread form as employed by nearly all Metric nations.

I bought a couple of 1/8 BSPT to 1/8 NPT adapters for my HKS GT wastegate when I converted to -6AN lines for it.