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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>When it comes to the 4-cylinder TR models, I am aware of four variations on cylinder head design: the original low-port TR2 head, the “le Mans” head which was a variation on the low port design, the high port head which came with most of the TR3s and the TR4 head with the smaller intake aperture.<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>But someone was talking to me the other day about a variation in the high port TR3 head. According to this guy, there was a variation in the thermostat housing, some of which were more sloping than rounded. He claimed the sloped design was more attractive as it lended itself to more shaving and thus a better, high compression engine.<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>I must admit I had never heard about this. I have three heads sitting in my barns and all have what appears to be the same, rounded underneath to the thermostat housing.<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>Has anyone heard of this?<br><br>Andrew Uprichard<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Times New Roman","serif"'>Jackson, Michigan<o:p></o:p></span></p></div></body></html>