Is it ok to mount the overflow tank higher then the rad. I only ask this because in all the cars I have looked at its mounted below or at the same height. I was thinking about mounting it behind the passenger shock tower in the engine bay where the charcoal canister used to be.

 

The overflow works on the cooling system's rising and falling pressure. Gravity won't have any effect on it. It'll work fine in that location, but be careful of exhaust heat with that plastic tank...

 

thanks, nad ya I am going to have to get a kinda lenthy hose to get round the the motor and exhaust.