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The carb you purchased requires a fuel pressure regulator...Holley makes a efi carb with a built-in regulator so a return line would not be used. Edit: a return line is still required...
What vacuum line diagram(s) are you needing? Do you have the 1977 assembly manual?
the pump has 1 less input for hoses. Do I get rid of the 3/8th tube and put a cap on the line? I believe the 1/4 tube was dripping fuel a bit so it must be the fuel line.
The Holley fuel pump you said had a built in regulator, so the return line would not be needed...
The 3/8" pipe is your feed line to the carb...
How are you going to plumb the tank vent?
OEM had a Tee connecting separator line to tank vent with a .035 Orifice restricting vapors to charcoal canister...
The tank needs a vent line, The fuel cap if using a OEM cap for a 75-77 has a higher relief pressure then a normal vented cap...
If you cap off the vent and use a OEM cap your new tank may implode...
The Holley fuel pump you said had a built in regulator, so the return line would not be needed...
The 3/8" pipe is your feed line to the carb...
How are you going to plumb the tank vent?
OEM had a Tee connecting separator line to tank vent with a .035 Orifice restricting vapors to charcoal canister...
The tank needs a vent line, The fuel cap if using a OEM cap for a 75-77 has a higher relief pressure then a normal vented cap...
If you cap off the vent and use a OEM cap your new tank may implode...
okay just to verify… the fwd or aft hardline is the supply line. I might have put a quarter on the line. Or the reason the 1/4 was leaking fuel was because it was returning what was in the line. Also you mentioned about the cap. Is the 77 OEM cap not okay? There wasn’t a cap in the package. There are vent lines. I don’t know if that would support the pressure equalization.
also the brown wire on the distributor is for coil neg… should I splice the tach wire before or after the capacitor. And also there looks like after the capacitor there is a 2 female connector. Will send pictures if requested.
okay just to verify… the fwd or aft hardline is the supply line. I might have put a quarter on the line. Or the reason the 1/4 was leaking fuel was because it was returning what was in the line. Also you mentioned about the cap. Is the 77 OEM cap not okay? There wasn’t a cap in the package. There are vent lines. I don’t know if that would support the pressure equalization.
also the brown wire on the distributor is for coil neg… should I splice the tach wire before or after the capacitor. And also there looks like after the capacitor there is a 2 female connector. Will send pictures if requested.
Yes, send a photo(s).
There is only 1 3/8" fuel line on the Holley fuel pump, that is your feed line...
You need to use EFI rated fuel hose on those connections i.e. fuel filter(s) Carb etc.
The small pipe (driver side) is just a vapor line going to the charcoal canister.
At the charcoal canister there would have been another rubber hose to front of carburetor...
That would be connecter to a PORTED or TIMED fitting on the front of the carburetor...
In your Sniper 2 instructions it shows on page 4 fig. 3 the front & rear view of the vacuum ports...
The TIMED SPARK PORT. Meaning, that when the throttle plate is closed there is NO vacuum at that port..
Only when the throttle plate opens to a certain point then a vacuum signal would be present..
On the back of the Holley carb there should be 2 ports, the larger would go to the brake booster, the smaller one can get capped off or used for dist. vacuum advance...
If the rear port is used for vacuum advance cap the Manifold Vacuum port on the front of carb...
Last edited by bmotojoe; Apr 29, 2026 at 08:30 AM.
Yes, send a photo(s).
There is only 1 3/8" fuel line on the Holley fuel pump, that is your feed line...
You need to use EFI rated fuel hose on those connections i.e. fuel filter(s) Carb etc.
The small pipe (driver side) is just a vapor line going to the charcoal canister.
At the charcoal canister there would have been another rubber hose to front of carburetor...
That would be connecter to a PORTED or TIMED fitting on the front of the carburetor...
In your Sniper 2 instructions it shows on page 4 fig. 3 the front & rear view of the vacuum ports...
The TIMED SPARK PORT. Meaning, that when the throttle plate is closed there is NO vacuum at that port..
Only when the throttle plate opens to a certain point then a vacuum signal would be present..
On the back of the Holley carb there should be 2 ports, the larger would go to the brake booster, the smaller one can get capped off or used for dist. vacuum advance...
If the rear port is used for vacuum advance cap the Manifold Vacuum port on the front of carb...
Three photos of the wire and where they should go. I got the extension harness and who would’ve guessed that the starter is not fun to get to. Since I’m going to have a bunch of wires that need to be snipped from the old harness, is there a way to disable the ac since that is a ton of hot wires. And lastly any recommendations for capping off the charcoal return line?
General location of the yellow wire connecting to that brown wire Top label for C- Or this spot here seems like it should go but there is a capacitor I believe next to it.
That is not a Capacitor, that is a filter for the tachometer...
Be very carful when working around those wires, especially in & out wires near the filter...
OK, so I pulled a spare filter from my stash...
Make your splice as close to the TACH plug at the distributor as you can, but also leave enough wire to make a clean splice...
And as far as snipping wires, my advice is get the dam thing running....then you are on your own as far as snipping wirers...
That is not a Capacitor, that is a filter for the tachometer...
Be very carful when working around those wires, especially in & out wires near the filter...
OK, so I pulled a spare filter from my stash...
Make your splice as close to the TACH plug at the distributor as you can, but also leave enough wire to make a clean splice...
And as far as snipping wires, my advice is get the dam thing running....then you are on your own as far as snipping wirers...
okay so that wiring is all done. I’m currently trying to clean up more of the last persons mess. As I have been putting a working radio in I noticed another oddity.
[img alt="This is speaker wire with his signature electrical tape.
"]https://cimg7.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/2000x1504/image_2582919522c3b60a1498704b4835479d02 6cfb2f.jpg[/img] This is speaker wire with his signature electrical tape. Goes into the main wire harness This came out the other side
