Ok guys, I have read enough about what turbo plugs are compatible with what engines.
So i made a mold to check the threads and taper of different plugs. One mold is made out of novarossi cto6 and the other from an os rp6 plug.
I will update later with some pics.
I have tested novarossi cto6 and ct6, os p5 and rp6, sh t3 and t4, alpha p3 turbo plugs.

The Novarossi glow plugs are the same in threads and taper as the Sh glow plugs.

The Os glow plugs are the same with the Alpha glow plugs and threads and taper.
​​​​​​
Between OS and Novarossi there is a slight difference in taper and thread shape.

​​​​​​Here is a picture of one of the molds I made, this is the novarossi mold with the sh plug.
​​​​​​