Where and how did you run your wires and relays? I have a 2bbl sniper (550-849) with the hyper spark dist (565-323) ignition box (556-151) coil(555-152) and in tank fuel pump (12-305) on the way for my 2bbl 390.
I’ll get you some pics tomorrow, but:
I made a mounting bracket for the hyperspark c/d box and mounted it under the passenger fender on the rear apron near the top. I ran the sniper power wires and the c/d coil and distributor wires through a small hole behind the passenger hood hinge. I loomed the c/d box power / ground wires and the ecu power / ground wires together from that hole and ran them under the fender apron to a hole at the front by the battery box and connected them with inline fuse holders directly to the battery cable terminals. (Connection doesn’t look the best so I will buy a top and side post combo battery later and attach them to the side posts for a cleaner install)
I made a mounting bracket /plate for the relays and ecu fuse and mounted them to the top edge of the passenger firewall. I ran the blue fuel pump relay wire through the firewall near the fuse block area and down the a pillar and under the drivers step plate all the way into the trunk with the main rear harness. I had to lengthen it a little to attach to the fuel pump plug in harness.
I soldered and heat shrunk every connection that I made. I also loomed every set of wires in TEK braided split loom.
I have not put the fuse in the c/d box connection yet to power it up so I don’t know if I am going to get any RFI or EMI from having those wires so close to each other yet. I shouldn’t, but murphy has a way of sneaking in.
My 12v switched power is from a relay triggered by the current coil + wire. Works great now, but I might have to re-think that one when I change over to the c/d box…not sure yet.
I will be un-pinning and removing several unused wires from the ECU main connector to clean it up some and see if that is causing my very minor RFI signals I think I see in my datalog. (No real performance issue that I’ve noticed yet, but I want to eliminate any possible issues down the road)
Why did you choose Sniper over other EFI? Like FAST or FI tech
I will be un-pinning and removing several unused wires from the ECU main connector to clean it up some and see if that is causing my very minor RFI signals
An un-terminated wire amounts to an antenna. I have unpinned the excess connections and it completely solved the RFI issue on a Sniper install on a Y block Thunderbird.
Well, to be honest, I did not research FAST. I did not like the way FITECH looked and it didn’t perform as well according to someone that I knew who was running that setup. Holley for me was a well known and trusted brand.
I will be doing that in the morning, provided my wife doesn’t throw a wrench into my garage plans. 
I will also run another data log afterwards to confirm it really helped as I firmly believe that it will.
I have rocket mans predapter 001 and I was thinking of using that keyed 12v source to operate the sniper and hyper spark.
That should work.
Here are the pics I promised: (yes, I still have some prettying up to do on some wires)
Good work, I like the idea of hiding the CDI box. Any concern with debris or road spray from the tire?
No, the box is fully sealed. I originally built the bracket as an enclosure box, but had no way to put the screws in to attach the box to it. So I cut off the enclosure part and left it as a mounting plate.
Mmm, not sure I’m going to mount the cdi box in the wheel well. The gravel road will not be kind…I do like the firewall mount.
Ok… do you need to use the tach output brown wire if using stock xr7 tach? I’m showing no rpm signal at initial cranking. I assume yes, but how do i wire it in? Thanks
I have an upgraded tach from rockettman that will use the brown tach wire when I switch over to the cd box ignition. Stock tach gets its signal from the coil wire that you can’t hook up with the cd type ignition. I would guess you could use the brown wire with the stock tach, but I don’t know for sure. That is probably a rockettman question… 
Update… don’t need that brown tach wire. My entire problem was a sticking relay!! When it wants you to cycle the ignition so it can upload to the ecm the relay wasn’t letting it turn off.
Awesome! Glad that one was easy.
Forgive me if this seems obvious to some.
I am putting the full hyperspark system in with the holley super sniper. I am not very well versed with creating circuits with relays.
How are yall getting the factory tach to work when the holley coil only connects to the distributor? Aka what is the old coil wire connected to? And what are you using for the switched power to the throttle body?
Pretend I’m a 5 year old that knows what these words are but not piecing it together lol.
The Sniper has a separate output wire (light brown I believe) that will drive an aftermarket tach. I don’t know if it’s going to be compatible with the factory tach, you may have to send it out to rocketman to be converted to modern electronics.
For switched power I’m using the coil power wire that comes from the ignition switch. I had previously removed the inline resistor so it’s getting a full 12V rather than the ~6V with the resistor. If you still have the inline resistor you’ll either need to remove it/bypass it by running a new wire directly from the post on the ignition switch. Another option is installing a relay, using that 6V power as the positive trigger to deliver 12V power directly from the battery/fuse box.
There is a provision for tach wiring in the manual but Not sure how happy the factory tach is with that as the xr7 tachs are a little different wiring then most. Someone else will chime in on the function of the factory tach. I have an aftermarket tach in my car and that’s as easy as hooking up a wire.
For the key on power make sure you grab that from a source that has 12v at key on and during cranking, this is important as not all key on sources have 12v during cranking. Like mentioned a common source is the pink resistor wire at the ignition switch. I choose to use an auxiliary relay/fuse box to add additional wiring under the hood so I included a relay for the ignition here too. I also used this for my electric fans and controller, 12v battery power to the radio and will be used for the sniper and cdi box stuff. I grabbed the 12v ignition source at the starter relay, this then is used to power a relay in the aux relay box to power all sources that will need it.
Thanks Diesel.
I was thinking of using the starter solenoid for the 12v, but wasnt sure that would work well. Plus the wiring in this car is horrendous to start with, my starter solenoid looks like a spider web 
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I see the instructions say the dark brown from the Holley is for aftermarket tachs, I’m hoping the factory tach will work with that so its as simple as connecting the old coil + to brown, but doubt that will be the case.
If you choose the starter relay make sure you use it to trigger a relay only, I wouldn’t use the starter relay to solely power those circuits.
I’ve reworked all my battery cables and terminals to clean up that area. It can get messy in a hurry especially when adding aftermarket components under the hood