Loading... Please wait...


Become a member

Valve Guides, Cast Iron, 3/8", .374" X 2.500" X .502" Universal, Sold in quantity of one each, order what you need.

  • Image 1
  • Image 2
Calculated at checkout

Product Description

 Universal Fit, .502" O.D. Guides

Cast Iron Valve Guides, .374" X 2.500" Long

Sold in singles, order quantity needed for your application.

$1.79 per guide


These can be fitted to many different domestic iron head applications running 3/8" valves.

.502" Outside diameter guides are the std of the industry.

This type of guide is used in heads which have "integral" guides. This means the guides are part of the casting and are not removable.

Heads are set up in a "Seat and Guide Machine" and each guide is core drilled, then reamed to .500".

Guides are then pressed or "driven" into place. Any extra length is then spot faced to fit.

In our shop, after the guides are installed, we take a .500" valve seal cutter to clean up any old remaining guide material from the seal side of the guides so .500" Positive seals could be installed, as well as the removal of any remaining, thin-wall iron material.

If needed, guide inside diameters are then fitted by either reaming or honing w/ Sunnen tooling.


  • .502" Outside Diameter
  • 2.500" Overall Length
  • .374" Inside Diameter (before installation)
  • Spiral ID: NO
  • Plain ID: YES
  • Material- Cast Iron
  • Manufacturer- Precision Engine Parts
  • Quantity included in purchase- One Valve Guide

We carry several different types of valve guides, both in Cast Iron and Bronze. Hardened guides are available in limited sizes.

Looking for something different? Special guides are available on a special order basis.

TECH NOTE: Aluminum heads always have some form of guide inserts. This type of guide is not intended for such heads. Applications w/ aluminum heads normally require replacement guides in the same type. If you're looking for replacements for aluminum heads, write to us and we'll advise. This site is in a constant state of construction, we offer much more then what is shown here.


    Alex's Parts- The smart choice in valve train parts~