Any ideas? Multiple spider replacements 98 Tahoe

Hey all, I am going to try and make a long story short..
98 Tahoe 5.7 271000 miles now

If you look at my history you can see I have had many issues with this. In 12/08 I had the spider unit replaced. I had bought a reman with warranty. 1/09 it failed, replaced again. Issue were continuous running lean on both banks. Misfire #5.

Replaced fuel pump 4/09 and again 8/09.

3/11 had the engine rebuilt, month later spider went bad AGAIN misfire #5.

This last week - less than 20000 miles on it, misfire #5. Spider bad. Replaced it didn't fix. Tried to tell me might be computer - just happened when I had the issues in 08 I had bought one (flashed to my VIN) never used it so it was under the back seat. Hooked it up, no change still misfire #5. The only thing he can think of is a bad spider again.... all wiring tested fine

My question is there something that could cause the spider to go bad on the same cylinder every time? It just seems odd to me that it is always the same cylinder on the units that go bad.

Any ideas or suggestions are appreciated thanks for taking the time to look.

It could be an electrical issue with #5. Probably need to trace it back all the way to PCM. Since you swapped PCM, that does not seem to be the issue so it could be between the PCM and the #5 connector.

//2000CAYukon

Also you need to check for a worn dist gear. Pull the cap and while holding some down pressure on the rotor see if there is any rotational play. NO ROTAIONAL PLAY IS ALLOWED.

Are you using the updated spider? A Delphi fuel pump?

http://www.amazon.com/Delphi-FJ10566-Fuel-Injector/dp/B000TYLIFS/ref=sr_1_3?ie=UTF8&qid=1343831869&sr=8-3&keywords=suburban+fuel+injector