<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_1_1455913856463_3874" dir="ltr">I have been told by 2 different machine shops that a hairline crack in the valve seat between intake and exhaust is not a big deal. They both referenced the iron head stock car racers that do it all the time. This is on two GT6 circle B heads I had magnafluxed. I was a little surprised to hear that and just as surprised to hear the same from a second machine shop. Both of these shops do a lot of work on circle track stuff. One I know also does a lot of drag race motors. Both also noted that it is questionable if I was trying to get 100K miles on a road going car but for racing not to worry about it. Check it anytime the head is off. the cracks are in line with a casting line in the valve pocket/port. </div><div id="yui_3_16_0_1_1455913856463_3874" dir="ltr"><br></div><div id="yui_3_16_0_1_1455913856463_3874" dir="ltr">Thoughts on that?</div><div id="yui_3_16_0_1_1455913856463_3874" dir="ltr"><br></div><div id="yui_3_16_0_1_1455913856463_3874" dir="ltr"> I also have an "A" cast head that is not cracked. The B head is supposedly better. I know this came up a couple of months ago but I don't remember the differences between the A head and the B head.</div><div id="yui_3_16_0_1_1455913856463_3874" dir="ltr"><br></div><div id="yui_3_16_0_1_1455913856463_3874" dir="ltr">Thanks, Brian</div><div id="yui_3_16_0_1_1455913856463_3874" dir="ltr">Foster, RI</div><div id="yui_3_16_0_1_1455913856463_3874" dir="ltr"><br></div></div></body></html>