valve guides exhaust and inlet?

[mfc]

hi all, ive got a set of valve guides sitting in the shead and im trying to work out if there inlet or exhaust [spread bore] there is no internal o ring grove so if there inlet there early type{im hoping there inlet}
cheers mark

[Reddirtbandit]

If you need to do inlet guides get them k-lined you can run less clearance etc, longer life, much better way than iron guides