[Rick Parker]

The Fel Pro # in question is #1645. 5/16" Thick Cork-Lam cork- rubber with steel core. They are fairly rigid and are not intended for use with sheet metal valve covers unless they are absolutely flat. The additional height is an added benefit.

I have previously used the 1"spacers described above. The locating holes for the valve cover bolts can effect how the spacers fit on a given head, some of the patterns are not very accurately done. The area of the rocker arm that contacts the spacer or cast aluminum covers in some cases is the area near the pushrod cup on the lower side of the rocker arm, not the top as you might think, or on the inner edge of the valve cover gasket sealing surface. Look at the area on the "End" of the rocker arm near the pushrod cup. When I used the spacers I had to relieve the area adjacent to each rocker arm about the width of the rocker arm. I used a sharp carbide 1/2" diameter cutter in a Makita. Spray the cutter with WD-40 or put wax on it so the aluminum doesn't build up.

Mark the area in question with a felt pen (after cleaning off with carb cleaner etc) install, run for a minute or two then pull the cover and look for an area where the ink is rubbed off by the rocker arm. Relieve as required.

Some of the later aftermarket head castings have the gasket rails raised to avoid the need for these aluminum spacers. It was good thinking on the design engineers part.

Rick