Hi everyone. Just fitted 200tdi into 1990 110. I have a 300tdi airbox that came with the engine. Original 19j air box has aa k&n filter in it. Was wondering how detrimental it would be to re use that. Filter us smaller but should breath easier. Air filter outlet to turbo is same size as turbo inlet so can't see it being overly restrictive. Any ideas, comments or sharing of knowledge would be welcome. ☺