Hello all. I'm putting together a basic, low HP power plant for an older Chevy 4x4. I go up & down in elevation & temperature a lot in this truck, so I'm really looking forward to the simplicity of EFI once it's properly configured. I have a new crate Chevrolet L31-R long block, a 4-bolt main Vortec engine for 3/4-1 ton trucks & vans from 96-??. There is a TH400 in the truck already. I bought a Holley Sniper EFI, Holley dual sync distributor, dual sync harness adapter, EP381 OEM in-tank fuel pump & MSD Blaster SS 8207. I plan on running dual fans in the truck as well. No A/C as of now. I've been looking over the installation instructions and have a few questions:

1. I've read it's best to get the engine running on fuel only before adding ignition control. I don't have an existing distributor and this is a fresh install. Any pointers on doing EFI and timing/ignition control at the same time?

2. Pin C (blue wire) on the 7-pin connector is for the fuel pump. Is this for triggering an external relay for the fuel pump or is there a built-in relay in the Sniper? I.E. Run the blue wire directly to the fuel pump positive power supply wire? Fuel pump is OEM to 1996 Chevy truck with Vortec 5.7. Nothing special amperage wise, but I think around 15ish amps.

3. As previously stated, I will be running dual electric fans from pins C & D on the 10-pin connector to trigger fan relays. Any special considerations or pointers here?

4. The one I'm really curious about, can I use the yellow pin B wire from the 10-pin connector to control the TH400 kickdown? If not, is there another wire? If so, any pointers on how to properly set this up. Thanks so much for the help in advance, Jeremy