I am currently rebuilding my 463.

Well later today I am taking my cylinder heads to school to replace the valve seals.

How do I know if the guides are machined for positive seals?

If they are not, how do I machine them to accept positive seals?

Thanks in advance for the excellent replies.:beers:

I'm pretty sure that the Merlins come machined for the 'good' seals.
easy way to check..............if they are not machined for them,the seals won't slide over the top of the valveguide.

Mine are.

pdq67

So are mine

Right on, thanks for the replies.

Mine don't have the guides machined for positive seals.:(