Firstfives.org

Are there any original options to relocate the coolant overflow tank? Like for example an E28 radiator with internal overflow tank? (Don't know if it exists.)

It's kinda in the way of my charge pipes since I flipped the M30B35 throttle valve to the other side of the intake. It's now directly facing the stock overflow tank.

E28's use the same setup, just shaped differently, so a different radiator isn't going to help. You need to retain a tank, and at a correct height (I'm pretty sure) as that little bleed hose between the radiator and the tank performs a vital role in bleeding off air in the radiator, plus of course you need to fill the system at the highest point. However, some E23 and E28 (and perhaps others) are either shaped differently or have the hose connections in different places, so that might help.

I'll fix something. Thanks for the info!