valve stem seals

[woody02]

I've decided to lap my valves in, fit new stem seals and clean the head e.t.c while im rebuilding my engine after because of a piston meltage. Thought I might as well do the head while it's all in bits.

The trouble im having is that I cannot get my valve stem seals to fit on top of the guides!!  I've done this plenty of times before on various engines and never had this problem (went on my first g no probs)   had my mates round to have a go to make sure it wasn't me making a mistake but everyone has the same trouble.
I've used the stem seals out my elring head set and i've also bought a few from vw and they are both the same, they just wont fit!!   Stressing me out because it should be a simple job.
Any help most appreciated!

[cheys03]

Early heads had 8mm valve stems, later had 7mm. Is it possible you've got 8mm valve stems and seals for 7mm stems maybe?

[woody02]

Possibly, I didn't know there were 2 sizes, parts guy at VW never mentioned 2 diff sizes, il give them a ring, thanks.