Otherwise 940 made in 1994 won’t serve you long enough. Don’t underestimate the importance of Volvo’s 2.3 engine cooling system. It’s better to choose fluid in combination of 1996 year, 2.3 volume of motor and engine code of B234G. Only Green antifreeze type is suitable and you’ll need 9.5 liters of it. There are some conditions in servicing cooling module at Volvo 940.
It’s obvious that every B230FB motor needs good service as stated by Volvo in instruction. If you choose other than Green coolant or use less than 9.5 liters, you can’t expect normal work. It will be advantageous to follow Volvo’s rules for 1996 940 service. Use your 2.0 engine longer in 1990 940 by keeping these rules.