Just musing, cylinder head refurb options

[1969Mk3Spitfire]

I’ve pretty much convinced myself that my single plug sooting issue is related to worn valve guides. I’m in no particular rush to act but just musing. 

It will probably become a winter project.

Based upon forum wisdom, what’s a sensible approach? (1) DIY job, are guides readily available? (2) have the guides replaced by a specialist, (3) get the valve seats done (for unleaded) at the same time, (4) service exchange head

Appreciate pros, cons and costs. Many thanks.

[Pete Lewis]

its relatively easy to tap/press in a new guide  we used a vice as we were confronted with a head looking more like a stack of organ pipes  all at funny heights

but they are not a hard press fit   a quick spin with some grinding paste and alls well with the seats 

pete