Radiator Cap

[Mopar2]

I have a 408 with a 22" radiator and fan shroud. When setting in line at a car show it wants to heat up to around 200 or 210, driving down the road is fine. What size of radiator cap should I be running and what size should I have on my 340.

Thanks Dan

 

[72Dart6pack]

15 lb cap is fine.

 

[norshorblufish]

What temp thermostat do you have in it 180 to 195 is I believe standard temp for t-stat. If you have a non electric cooling fan the temp would go higher because you aren't move and less air moving over the radiator.
Have the cap test to see if it holds pressure It might not be the problem at all.