So now I have to figure out if I can either machine the retainers down

 

Is that just a pair of visegrips and a belt sander to take material off the top surface? or more complicated?

 

..and if you don't daily it just put a Viton O-ring on each inlet valves and don't use stem seals. The exhausts are always under pressure so don't get oil in, and the O-ring drops the oil onto the top of the valve guide for the inlets. Cars used to have them before these flash new stem seals we use now, but old cars always used to smoke a little.

You could try talking to stu - ''thomas' dad'' i recall speaking to him about some custom stem seals in the motor which for lack of a better description was like an umbrella that slid over the valve stem and stopped oil dribbling down.

Cheers guys, problem isnt valve stem seals anymore....just spring retainers.....finding the right ones for the springs I have seems to be near impossible.

 

And nah the machining would be done on a lathe....none of this dodgy belt sander stuff. lol