Toronado V8-307 5.0L (1982)
Valve Guide: Service and Repair
Fig. 10 Valve guide bore marking
Valve stem guides are not replaceable, due to being cast in place. If valve guide bores are worn excessively, they can be reamed oversize.
If a standard valve guide bore is being reamed, use a .003 inch or .005 inch oversize reamer. For the .010 inch oversize valve guide bore, use a .013
inch oversize reamer. If too large a reamer is used and the spiraling is removed, it is possible that the valve will not receive the proper lubrication.
Occasionally a valve guide will be oversize as manufactured. These are marked on the cylinder head as shown in Fig. 10. If no markings are present, the
guide bores are standard. If oversize markings are present, any valve replacement will require an oversize valve. Service valves are available in standard
diameters as well as .003 inch, .005 inch, .010 inch and .013 inch oversize.
