Injector check ball in fuel rail

[87toysupratt]

I just changed 2 injectors(#4 and 8) due to a cylinder contribution test. When I removed and looked at the #4 injector I could see the check ball was missing and I believe its somewhere in the fuel rail. I ran the contribution test after replacing both injectors and #4 passes and # 8 fails. I think the ball is stuck somewhere in the head between #6 and #8 and was wondering if anyone has encountered this issue and knew the best way to resolve it.