O-Rings - Cu Gaskets

If you purchased one of the first Keith Black Aluminum Blocks, you would have received these instructions to modify your steel heads with a receiving grove for the o-rings in the new block. 
when aluminum heads became available the O-ring was installed in the softer alum head and the sleeve grove was widened to become the receiving groove.
Hoops  Height Width Dimension exposed  A x B
Standard  .098 .050 .021 to .031 .050 x .070
Tall .100, .105, .110   .021 to .031 .050 x .070
Wide   .058, .060 .021 to .031 .050 x .070
O-Rings (SS-Wire) D  C with
receiving groove
C without A x B *
.041 .038 to .040 .030 .030 .030 x.060 *
.052 .049 to .051 .041 .039 .040 x.090 *
.062 .059 to .061 .051 .046  
Note * -- Old -- KB, BAE, TFX sleaves are cut to .020 x.070 wide (SCE gasket recommends more)
Note: sleeve should sit .007 above aluminum block ( Dry Blocks or older blocks without using water)
Note: hoops are generally used with .070-.120 gaskets, o-rings are used with .035 .050 gaskets-
( I have used o-rings for a whole season without the actual Cu gaskets)

A Original dowel pin

B Extra head stud with         locating dowel pin

New location dowel pin