do they have a history of overheating easily?

 

According to sources.. No
If u install aftermarket or non
stock heads, u have to have them
drilled for steam holes.
Peoples did it wrong and got
overheating issues.

 

Depends who you ask, I think there is alot of misleading info on this subject due to people either putting on heads without steam holes or drilled wrong as mentioned above. I havent heard of anyone on this message board having an overheating problem. I think a .060 overbore with tons of compression and or a bad or in adequate cooling system may tend to run hot though!

 

I have had numerous 400s over the years, including one that lived in my 83 HO car for somewhat over a decade (and will live there again someday); I've never had any unusual problems even with the stock cooling systems.

The early ones, that came as 4-bolt main blocks, had somewhat thinner cyl walls, and were a little more prone to this than later ones; by the time they changed the casting in 73, they had already acquired the reputation, which is now part of the "lore"; so now, any time some doof puts a leaky radiator in a car with a 400, or screws the cooling system up in whatever other way (like using a flex fan or stupid stuff like that) , it's automatically "proof" that 400s "run hot"..... BS

 

well my 406 has a 5 core aluminum radiator dual 14'' electric fans
Brodix -8 aluminum heads don't know if they have steam holes or not ???
I was at the track last week and from my first to last pass I lost 8 mph

that is why I wondering
I have the stealth ram intake and there wasn't another port to pu the temp guage back on