Pipe Diameter?

Beaker™

Slightly Unhinged........
Nov 21, 2005
1,900
0
C:\UK\Glos
Anyone know what size the inside bore of these three pipes are?

s6lrnn.jpg
 

Beaker™

Slightly Unhinged........
Nov 21, 2005
1,900
0
C:\UK\Glos
Thanks guys, is it ok to use vac hose for the header tank as well then? Or would it be safer with 8mm coolant hose?