DOGGM

Hello everyone, I am obviously new here and I am hoping that someone can help me with a very unusual spider assembly problem. I installed a new (aftermarket) fuel pump on my chevy suburban and a new Delphi spider injection assembly. After driving about 300 miles the pump went bad. I replaced the pump w/ a new Bosch pump and drove about 30-50 miles and the spider injection line on cylinder 6 or 8 started leaking. Although, I thought it would be hard to believe that the Delphi part was a defect I had another brand new one sent to me. I then drove approx. 300 miles and the spider assembly started leaking again on the same 6 or 8 cylinder. Does anyone have any info about what might be going on before I loose the rest of my hair! Any help is greatly appreciated.