Some places will charge as much as $1000 for a valve adjustment as it can take all day. Also most places will not have the needed shims so you might need to provide the kit.
We do carry the needed shim kits: SHO Source Shim Kit
It is something you can do in a day: SHO Phoenix Project
When it gets done you need to replace the valve cover gaskets: 3.0L/3.2L SHO Valve Cover Gasket Set 89-95
If your valve cover grommets leak we have them as well: 3.0L/3.2L SHO Valve Cover Grommets 89-95
you wshould also replace your wires and plugs as well: Engine- Ignition - SHO Source
We do carry the needed shim kits: SHO Source Shim Kit
It is something you can do in a day: SHO Phoenix Project
When it gets done you need to replace the valve cover gaskets: 3.0L/3.2L SHO Valve Cover Gasket Set 89-95
If your valve cover grommets leak we have them as well: 3.0L/3.2L SHO Valve Cover Grommets 89-95
you wshould also replace your wires and plugs as well: Engine- Ignition - SHO Source
