<html><body><div>Not sure what it's for, but it does exist on my engine and the plug that fills that hole uses a 1/2 BS or 7/16 WW socket. Again not sure what it's for. But I'm pretty sure if you don't plug it, you're going to have some problems.</div><div> Also look at the back of your block, there is a hole that used to fit an oil feed that was eliminated on 100 engines, but is used to feed oil to the 100S distributor I believe. The hole wasn't plugged on my block and I didn't notice it until I had the engine back in the car and fired it up and it leaked oil out the hole. Standing behind your engine, it's a little off center to the left and about an inch below the head. I've been told it should be a brass plug. I made an aluminum plug and pressed it into the block.</div><div>Steven Kingsbury </div><div> </div><div><br>On January 17, 2021 at 12:25 PM, Michael MacLean <rrengineer.mike@att.net> wrote:<br><br></div><div><blockquote type="cite"><div class="msg-quote"><div style="font-family: times new roman, new york, times, serif; font-size: 16px;" class="yahoo-style-wrap" data-mce-style="font-family: times new roman, new york, times, serif; font-size: 16px;"><div data-setdir="false" dir="ltr">Can someone please tell me what this hole is for?</div><div data-setdir="false" dir="ltr"><br></div><div data-setdir="false" dir="ltr">Mike MacLean<br></div></div><div class="_stretch"><span class="body-text-content">_______________________________________________<br>Support <a href="http://Team.Net" data-mce-href="http://Team.Net">Team.Net</a> <a href="http://www.team.net/donate.html" data-mce-href="http://www.team.net/donate.html">http://www.team.net/donate.html</a><br>Suggested annual donation $12.75<br><br>Archive: <a href="http://www.team.net/pipermail/healeys" data-mce-href="http://www.team.net/pipermail/healeys">http://www.team.net/pipermail/healeys</a> <a href="http://autox.team.net/archive" data-mce-href="http://autox.team.net/archive">http://autox.team.net/archive</a><br><br><a href="mailto:Healeys@autox.team.net" data-mce-href="mailto:Healeys@autox.team.net">Healeys@autox.team.net</a><br><a href="http://autox.team.net/mailman/listinfo/healeys" data-mce-href="http://autox.team.net/mailman/listinfo/healeys">http://autox.team.net/mailman/listinfo/healeys</a><br><br>Unsubscribe/Manage: <a href="http://autox.team.net/mailman/options/healeys/airtightproductions@icloud.com" data-mce-href="http://autox.team.net/mailman/options/healeys/airtightproductions@icloud.com">http://autox.team.net/mailman/options/healeys/airtightproductions@icloud.com</a><br><br></span></div></div></blockquote></div></body></html>