IE valve guides directly replace the OE guides providing longevity, reliability, for your cylinder head build.
If your cylinder head has had the valve guides replaced previously, it is recommended to confirm the inside diameter of the holes in the cylinder head before installing new guides. In some cases, the holes in the head have worn, requiring valve guides with larger outside diameters to be used. It is common practice to use oversized guides only where needed; they do not need to be used unless that particular hole is out of specification. Before installing oversized valve guides, be sure to ream the holes to the correct diameter to include the proper press-fit.
Recommended Clearances
Every engine builder will have his or her own specs, but as a general rule of thumb, we use the following valve-to-guide clearances.
Ferra Stainless Intake - 0.0008" to 0.0012"
Ferra Super Alloy Exh. - 0.0013" to 0.0015"
Ferra Stainless Exh. - 0.001" to 0.0015"
Supertech Stainless Intake - 0.0014" to 0.0024"
Supertech Stainless or Inconel Exh. - 0.0018" to 0.0028"