Just removed my FSA carbon Pro Team Issue cranks and the bottom bracket is a Shimano Dura Ace.
I thought all FSA was ISIS, so are they actually the same.

Thet aren't. FSA used both standards.

No, ISIS has 10 splines, Octalink have 8.

As you've found, some FSA (and other road chainsets) are Octalink.

That's ok then. Please tell me octalink is octalink i.e 105 is the same as Dura Ace.

octalink 8 splines
isis 10 splines

no dura ace and XTR share a spline system XT and below + ultegra and below share a spline system …iirc the splines are 1mm shorter or thicker cant quite remember just that they are different

Got an Italian thread used Dura Ace B/B going spare if anyone needs.

no dura ace and XTR share a spline system XT and below + ultegra and below share a spline system …iirc

All road octalink BBs share the same spline system.

so is it XTR and all road that share the same splines then? coulda sworn it was only XTR and duraace that shared – been ages since i had to deal with octalink ….

All road octalink BBs share the same spline system.

No they don't, Ultegra/Dura Ace/XTR are the same, shallow, splines, 105/XT/LX etc are deeper.

You're close Terry, Ultegra's the same as DA!

No they don't, Ultegra/Dura Ace/XTR are the same, shallow, splines, 105/XT/LX etc are deeper.

You're close Terry, Ultegra's the same as DA!

The 105 octalink bb I have here has the same splines as the ultegra one in my pompino.

105 is definitely the same spline as DA and Ultegra, though i think somewhere lower down the road range they use a spline the same as XT/Deore.

though i think somewhere lower down the road range they use a spline the same as XT/Deore.

Quite possibly. The cheap road stuff always used to be square taper, was unaware that they did some splined versions before switching to external BBs.

Simples!