Out of curiosity, could I replace my rather worn and crusty metal coolant reservoir with a newage style plastic tank? The water pipe connections look like they're in similar locations but I'm unsure if it will just bolt in or not.

My car is 1997 Version 3 Sti

 

classic expansion tank holds more volume than later newage metal & plastic tanks iirc

 

Thanks, so I would be reducing my cooling capacity slightly by doing the swap. Has anyone done it on here? Also interested to hear why people haven't done it.