318 LA-Valve Stem seals pict needed!!

Hello all!!I've got 2 heads that a friend gave me,he says it's 318 heads but he smokes too much and i dont know if i can trust in hes memory.The thing is that the guy that is working on him(to bring him back to life after 7 years)said i'll have to buy a new kit of Valve Stem seals,so i did .But the seals that i bought for 318 heads were a lot smaler than the one that he took out from the heads(Higher).The guy that sold me sayd that this is the 318 seals!
So i want to have a look at some picture of the standard Valve seals.Something is wrong here and i got to discover what it is.
How do i identify if it's 318 heads or not?