Well. If you think about it the heater core also bypasses the thermostat. In our cars it dumps back into the engine. On some GM products it dumped directly into the rad. As long as you get the engine up into the 180 range or so. It really does not matter if it is regulated by a drillled hole or the tstat opening. What Tom is looking to do is encourage flow through the head and get the temps equalled out better. Be interesting to watch one of those heads warm up with a non touch heat gun. Even the 199-258 experience unequal wear in the cylinders. I have always related it to getting that long block to heat/cool equally. Sent from my BlackBerry® wireless device from U.S. Cellular -----Original Message----- From: Bruce Griffis <bruce.griffis@xxxxxxxxx> Date: Sat, 6 Feb 2010 09:25:31 To: <das24rules@xxxxxxxxx>; AMC, Rambler, Nash, Jeep and family<amc-list@xxxxxxxxxxxx> Subject: Re: [AMC-list] AND ANOTHER THING 195.6 I was wondering about the drilling the thermostat thing. If the t-stat button causes it to open to let coolant circulate, isn't drilling a hole in it kind of like leaving it always open? Or is the hole small enough so that there is only a small amount always circulating, then when it opens it gets enough flow to keep it cool? _______________________________________________ AMC-list mailing list AMC-list@xxxxxxxxxxxx http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com _______________________________________________ AMC-list mailing list AMC-list@xxxxxxxxxxxx http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com