I've just got a couple questions about lash caps on a type 4 engine.

What are they generally used for?

Do you have to make any geometry adjustments like you would for the 911 swivel feet adjusters?

I have them for my motor, they are due to the stainless steel valves being softer on the tips. (helps prevent damage to the valves)

Yes, you need to adjust the geometry of the valvetrain.

You can get lash caps of various thickness too. You will have to make sure they do not hit the keepers too. I used them on all the valves in the race engine, even the titanium ones and never had stem mushroom problems.

The reason I was wondering is after I bought the car, I replaced the valve adjusters. On one side of the engine the adjusters were pitted pretty good, and if my memory still serves me, the exhaust valve stem tips had some pitting as well. This side of the engine is quite a bit noisier than the #1/#2 side. Someone along the way suggested that this could quiet it down some.

Some engines use lash caps as a means of adjusting the valves instead of the threaded adjuster like we use. In a stock Type IV, the use of lash caps are a band-aid, IMHO.

If the valve stems are pitting and mushrooming, the lash caps will prolong the life of the valves.