Ball Joint Thread Size

[The Rovering Member]

l need a Nyloc nut for a top ball joint. It's a replacement but one from the last century that l've had sitting on the shelf sans the nut. Can anyone narrow down the thread choices if indeed some replacements have been manufactured with threads different to the originals?
The bottom joint measurements are welcome too.

 

[jp928]

Get a thread gauge, a must have tool IMHO! With pitch and OD you are golden.
55 Whitworth & 60 Metric & US Thread Pitch Gauge Checker Measuring | Wish

 

[The Rovering Member]

I might just do that though l don't think l'll use Wish. Thanks.

 

[jp928]

Agree, Wish takes forever down here.......These gauges are vital when working with tapered threads - BSP threads can be just 1 different from NPT, as in 1/8 bsp is 27tpi, 1/8 NPT is 28tpi. Or maybe the other way around? Mazda use 1/8 BSP on their older engines.