All 66 V8s w/o A.I.R. came with 180 degree stats, those with A.I.R. came with 195 degree stats. Cylinder wear can occur with too cool an engine as well as too hot an engine. Published optimum performance figures I've seen for water temp is between 170 and 185 or so and optimum overall operating water temp is about 180 to 200. If it runs fine now and doesn't overheat with the 195, I'd use the same. With summer coming on, the 180 may give you a little more buffer zone against overheating when caught in traffic if that's a concern.
I've heard of drilling a hole in the stat, either 1/16" or 1/8", especially on a big block when the bypass hose is removed. Many new cars come with a bleed hole (or holes) in the stat to avoid trapping air. Drilling a hole is free and couldn't hurt if your replacement doesn't have one. You can do some research on the web and, for the price of a gasket, remove the stat and drill a hole in it. People will say they've run stats for years with no stinking hole in them and never had a problem. People used to drive on 2-ply/4-ply rating bias tires too but technology moves on. :*) Dale McIntosh <http://www.chevellecd.com> 1966/67 Chevelle Reference CDs ChevelleStuff.com <http://www.chevellestuff.com> ACES #1709/TC GOLD #92 <http://www.chevellecd.com> _____ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Thursday, April 26, 2007 3:43 PM To: Chevelle List Subject: [Chevelle-list] Thermostat ?'s I am replacing a leaking thermostat gasket and will replace thermostat while apart. Currently it has a 195* and works fine holding temp a 195*. Autoparts store suggested to put a 180* to run it a little cooler. Good, Bad or Indifferent? Secondly: I have read in the past about drilling an 1/8" hole in the thermostat flange to relieve an air bubble if it forms at the thermostat. Anyone do this? Autoparts store said many already come with a hole. The Stant I bought did not. Thank you, Krister Meister '66 SS #'s _____ avast! Antivirus <http://www.avast.com> : Outbound message clean. Virus Database (VPS): 000736-2, 04/26/2007 Tested on: 4/26/2007 4:25:40 PM avast! - copyright (c) 1988-2007 ALWIL Software.
