I have a 396 BB that is rebuilt to a 402
I have a cam that is more than mild
3.42 posi and stage 2 shift kit 350 tranny
stock 5 blade fan and clutch with stock shroud
temperatures get between 40 and 100 ' F during the year that I drive it
stock water pump
new 4 core rad and new stock cap
car has been tuned to perfection by my mechanic one month ago
overheating problem, this setup is all new, and I want to stay with a stock looking engine compartment
first thing I wanna replace is the thermostat since it is the cheapest, then go from there, but which one is best?
all advice welcome.
Well, you really didn't tell us much about the "overheating" problem at all. But, I am going to guess...
The inherent problem with everyone doing "performance" upgrades to the "used to be" stock engines (which would be boring, VE improvements etc..) is that you are making more horses. While this is a wanted and good thing... the OTHER THING that you have to do is UPGRADE your cooling system because you are making more waste heat. It's that simple! I have seen this countless times!!!
So, having said that.. the thermostat will NOT make one ioda of difference with regard to cooling per se. It just is a "gate" that regulates the specified tempeture.. and if the system will NOT operate correctly in the BTU removal department.. the thermostat will spend its life in the wide-open position.
So, having said that.. the best thermostat is indeed a 180 high flow like a Mr. Gasket or Mildon that you can easily get from Summit.
I know you want to keep your engine looking stock... but upgrading to other "almost looking stock" components can help things appreciably.
The three things that will be the best upgrades are (in the order of effectiveness):
1. Radiator surface area (Find a large tubed aluminum lookalike (stock that is) and paint it black... and usually no one will know the difference .. yet you have made a 30% improvement in your cooling. The best is Fluidyne.. go here.. http://www.fluidyne.com/pl_hpdomestics.html
but they do NOT look like stock. Also, you can seek out a heavy duty radiator that was used in your application for air etc .. but the aluminum is the way to go if you are going to spend any money in my opinion.)
2. Coolant flow improvements (Get a Stewart's Stage I or II and paint them the engine color. Again, most people can't tell the difference and yet a great upgrade)
3. Airflow improvements. (Use the factory heavy duty cooling fan (seven blades)
I will guaranty you if you do these.. you will NOT have cooling problems.
Cap the system off with at least a 12lb cap... 25/75% mixture of antifreeze to water and you are good to go for your temperature specifications.