Normal operating temp for the LT1 is 160 degrees. (same as the temp rating as the top t-stat)
If you are normally running 20 degrees warmer than your thermostat....you have a cooling system problem.
Check, raw water pump flow, look for leaks from the circulation pump, and make sure that you have the correct t-stats and that they are installed correctly and are operating correctly...search for blockages in the cooling passages.
Note the top t-stat needs to be a 160 degree one, with a by-pass hole drilled in it. Make sure to get the mastercraft one...there are many automotive ones that won't work.
Last edited by Jorski; 09-22-2011 at 03:47 PM.