Does anyone know the thread size and pitch for 1st gen diesel injectors (thread into head)? I am in the process of buying a diesel compression tester and the adapters included in different kits list two different sizes: M24 x 2mm and M24 x 1.5mm. Also, any suggestions regarding best compression testers? I need one which I can use with both the Dodge and an "86 VW Golf diesel (VW glow plug thread I believe is M12 x 1.25, injector is M24 x 2mm). Thanks.