Originally Posted by wave_crusher
I planned on running two thermostats, one to turn one fan on at 180* and the second to turn the 2nd fan on at 200*. I have the actual setup on my computer at home, but I believe it was all in one harness that was a standalone system. I don't believe there is software on the PCM in 96 to control electric fans either
Correct, you have to swap to a newer computer (LS1-B 512k) to get electric fan control out of the PCM if my memory serves. I did this on my 2000 k3500, but haven't put electric fans in it. EFI live to reprogram the brains and then tune away as needed. Used on 2001-02 LS1's and the 4.8/5.3/6.0s from 99-02, as well as the 01+ g-vans with 4.3s and 5.7s.
As for the spider system upgrade, If you don't have sticking poppets or cracked hoses, it's not worth it. I considered it at one point, but given the option, I'd change over to the marine intake for the v8's and run traditional injectors (also a gen3 coil swap would happen). Thinking of what that tubing in the plenum does to airflow gives me chills. Poppet valves on the end suck, but if they're clean, they do ok, and the electrical valve is still used, just upstream at the distribution block. Once your engine is up to temp, losses from wall wetting and intake stuff drop off significantly, but if your system is damaged, mileage/hp/driveability will improve. You'll see a bigger gain going to the marine intake than swapping the stupid spider for another stupid effing spider distribution system.