Temp
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
The answer to your question is 180 degrees...if the cooling system is working properly. Engines & cooling systems were originally designed to operate at 180, and the '68s had 180 deg. stats in them. If yours has a 190/195 degree stat, you should change it out with a 180 hi-flow stat. If it already has one, your cooling system might need a good flush or cleaning...or have some other component problem.
Pro
Joined: Dec 2006
Posts: 582
Likes: 3
From: Glen Allen (Richmond) Virginia
Here we go again, anything over 200 is "pushing the envelope" 190-195 gives you a little wiggle room. The airflow on these cars never was great but with the new dewitts radiator and a good fan and pump setup you should be able to stay under the 200 mark even with cast iron heads. I have a 69 with a 427 stroked and punched to 469 cubic inches. Never goes above 195 even on 100 degree days.
CF JASOC Member
Joined: Feb 2006
Posts: 8,040
Likes: 34
From: Downtown Annapolis, MD. The Future is where we all have to live. Let's not screw it up.
St. Jude Donor '08-'09-'10-'11
Burning Brakes
Joined: Feb 2005
Posts: 1,235
Likes: 0
From: Mesa AZ
the original temp guage doesn't hit red untill about 240* . so G.M must have thought if it stays under 240* then don't worry about it. i however don't want my engine running that hot . if it gets up to about 220 (which it will once in a while since i have a coolant leak) then i start to get concerned. if you have a stock setup it sounds fine, of course you can upgrade radiators and fans if you feel it is necesary
Le Mans Master
Joined: Nov 2001
Posts: 8,800
Likes: 1,943
From: LONG ISLAND
2025 C3 ('68-'73) of the Year Finalist - Unmodified
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big block 3x2 here went from a 5 blade non a/c car fan to a 7 blade ( still an original GM fan ) thats for an a/c car & usually doesnt go over 180 - except for extensive idling in the summer heat in traffic it may go to 190 but i have never, ever seen it go higher then that.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Later model vehicles are designed to run at 195 or higher. The 1960's and early 70's cars were designed for 180 degrees and had 180 stats in them. Can they run hotter? Sure... Should they? I guess that's up to the owner.
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