InstantForum.NET v4.1.4Y-BlocksForever Forumhttp://www.y-blocksforever.com/forums/jculver@y-blocksforever.comWed, 08 Feb 2012 22:20:35 GMT20http://www.y-blocksforever.com/forums/Topic9143-11-1.aspxThank you for that info, Glen.Mon, 03 Mar 2008 17:26:19 GMTgary534http://www.y-blocksforever.com/forums/Topic9143-11-1.aspxThe recommended way is to just run the 1/2" tap into the 7/16" threaded hole. John has used this method and states that it worked fine.Mon, 03 Mar 2008 16:26:36 GMTGlen Hendersonhttp://www.y-blocksforever.com/forums/Topic9143-11-1.aspxIf you drill out a threaded 7/16 hole in the block to the recommended bit size for a 1/2" tap, will the bit remove all of the 7/16 threads to leave a clean hole to tap to 1/2"?Mon, 03 Mar 2008 14:12:58 GMTgary534http://www.y-blocksforever.com/forums/Topic9143-11-1.aspx<SPAN style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman'; mso-bidi-font-size: 10.0pt; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA"><FONT color=#000000>Heads need to be able to use ½” head bolts.<SPAN style="mso-spacerun: yes"> </SPAN>Stock factory heads can be drilled without hitting water so that ½” head bolts can be used.<SPAN style="mso-spacerun: yes"> </SPAN>Likewise should be the same with any aftermarket replacement heads.<SPAN style="mso-spacerun: yes"> </SPAN>One idea is for the head bolt holes to be ½” except for a shoulder at the top to accommodate a 7/16” head bolt.<SPAN style="mso-spacerun: yes"> </SPAN>If using a ½” head bolt, then the shoulder is simply drilled out.<SPAN style="mso-spacerun: yes"> </SPAN>This feature is already on a variety of the SBF aftermarket heads so the heads can be used on either 302’s or 351W’s.</FONT></SPAN>Fri, 04 Jan 2008 07:35:57 GMTTed