<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">I weighed both blocks this morning, and discovered that the “TR6” block weighs about 11 lb more than the GT6-only block. The primary difference seems to be that the cylinder walls extend about 3/4” deeper into the block to accommodate the added stroke of a TR6, and the related casting and webbing. Don’t want the extra weight, so I think this block will go back on the shelf for the day I build a TR6 motor. They must have made a running change at around the time the GT6 late Mk II or when the MkIII was introduced to standardize parts across the model range.<div class=""><br class=""></div><div class="">Scott<br class=""><div class=""><br class=""><div><div class="">On Jan 7, 2018, at 7:16 PM, <a href="mailto:Gt6steve@aol.com" class="">Gt6steve@aol.com</a> wrote:</div><br class="Apple-interchange-newline"><div class=""></div></div><br class=""></div></div></body></html>