Thread size in head for head steady stud, 650SS, Atlas?
Threaded Holes - Aluminium Heavy Twin Heads.
All threaded holes are Whitworth form (with 55 degree thread angle).
Dominator, Atlas & Commando - for the 3 head/barrel studs - 3/8 BSF x 20tpi
Atlas - Headsteady centre stud hole - 3/8 BSF x 20tpi
Dominator, Atlas & Commando - intake rocker cover stud hole - 5/16 BSF x 22tpi Dominator, Atlas- 2 oil inlet on top of head - 5/16 BSF thread x 22tpi Commando - 2 oil holes on side of head + 3 headsteady bolts - 5/16 BSF x 22tpi Dominator, intake port manifold - 1/4 BSW x 20tpi
650, Atlas and Commando-intake port/manifold - 5/16 BSW x 18tpi Dominator, Atlas & Commando- rocker spindle cover plate screws (pre 66-short) - 1/4 BSW x 20tpi
Dominator, Atlas & Commando- exhaust rocker cover studs - 1/4 BSW x 20tpi
Thank you for your quick and detailed answer. Exactly what I needed to get some parts before brexit, which will make it more costly and delay delivery for us who remains in the EU.