Saab 99 FI pump upgrade

[GOLFGURU]

Hi all, thinking about upgrading my 3 port bosch pump with a similar spec 50ltr.per hr. bosch 2 port pump. I think it could work if i plug off return line from the pump since the f.p.r. takes care of the pressure..Not sure if this move is safe??My check valve is not holding residual pressure soooo...I'm gonna try to have it looked at again at python,they did a great job bringing it to life after it sat for 28 years..Maybe the valve just needs to be cleaned?? Thanks for any advise...Joe