L78 Holley Rebuild...

[VintageMusclecar]

Randy;

Toms car is a low mileage "survivor" (am I even allowed to use that term???), and as such he elected to keep the carb in its current state of aging...or "patina", if you will, as a fully restored carb would certainly stick out like a sore thumb among its 38-year-old unrestored surroundings.

Eric

[WILMASBOYL78]

Looks like the doctor did another great job....it's great to have a guy like Eric to help keep the "fleet" in good running order. Sending out the carb from our lawn mower tomorrow

[SS427]

[ QUOTE ]
Next issue was the Borg/Warner needle & seats that had been previously installed. These units are responsible for more junked float bowls than I can count.


[/ QUOTE ]

That made this thread worth the read (in case some of you didn't think it was already ). I KNOW that I have used the BW needle and seat on many rebuilds and have suffered many a floading condition and/or leaking afterwards. I never gave the needle and seat a second thought as being the culprit. Thank you very much for that information. Now if I can only retain that little tidbit of information in my pea sized brain.

[VintageMusclecar]

Perhaps I should clarify a little bit in regards to the B/W needle & seat issue;

It's not so much the fault of the component as it is the potential for damage by the installer. If you've ever taken notice, you can only thread a genuine Holley needle & seat down into the float bowl so far before the nut dis-engages the top of the needle & seat, preventing you from turning it down any farther where it could damage the boss where the O-ring seals.

On the B/W unit, due to the design, you can easily thread the needle & seat down far enough to do damage since the needle & seat itself contains the means of adjustment (screwdriver slot) as opposed to the 5/8" nut used on the genuine Holley part.

If someone was having issues with the carb that led them to believe the float levels might've been too high (such as a heavy or sinking float), one might try to lower the adjustment to the point where the extended threads on the B/W component start to thread themselves into the lower O-ring sealing boss, which in turn ruins the float bowl.

The other common result of the B/W needle & seat is stripping needle & seat threads right out the top of the float bowl. If you'll notice, this design has a reciever groove in the bottom of the lock nut. The nut is only designed to go on with this reciever groove facing the float bowl to compress the O-ring on the top of the needle & seat to seal it externally. I can't begin to count how many of those nuts I've seen installed upside-down...the result?...a leaky needle & seat that naturally prompts the mechanic to try to snug the nut down just a liiiiiiiiiiittle more to try to stop the leak. The result?...cranking the nut down only serves to draw the needle & seat straight up out of the float bowl, taking the bowl threads with it.

These are just a few of many reasons why I'm so adamant about using only OEM quality parts in my rebuilds & restorations.

Hopefully this will save someone a float bowl or two somewhere down the road.

Eric

[Jeff H]

Carb looks much better with the correct needle and seat and primary bowl. I sold my 4557 months ago for money to continue the restoration the JL8. It was dated wrong for my car anyway. I would like to get a more correct looking Holley 780 for my L78 and don't want to waste money on the 3310 since it's been messed with already. If I find a decent carb, I will be sending it your war Eric. Can't wait to hear how well this Nova runs with the rebuilt carb!

[Rixls6]

Great read.
Thanks Eric for the "insider" info about the needle & seat.
All my carbs would definitely be going to you when they need restoring.

[Mr70]

"I also noticed in the pictures that your green colored TCS plug wire that mounts to the switch on the passenger side head has a brown colored plug head on it. I was told that the brown colored plug heads started to surface on the mid to late seventy production cars and the earlier ones used a grey colored plug which is what the repro ones are colored. I had to get a repro one for my car because that portion of the wire was hacked off years ago by the previous owner. Luckily I still had the wiring and black colored plug head that plugs into the TCS solenoid on the intake. I found this coiled up in the wiring gutter..."

I've only seen either the Black or the Brown TCS plug installed here originally on the 1970 Big Blocks so far...Cars like Bill B.,Dennis C.,Dave G.,Tony P.,& Dean R. survivor LS-6's to name a few.
I've only encountered the Grey on Small Blocks & have factory photos showing Grey on them too,but still not certian it was exclusive to just the SB.

[Mr. Chevy]

Rick, the guy I spoke to about these plugs was out in California when I was calling around looking for the original style plug for my car. He was the one who gave me the info and he seemed to be very knowledgeable. I can't remember the name of the place but they dealt only with old car/musclecar electrical items.

He did state that the grey plugs were used on Big Block cars but like I said, earlier. I have never heard of a black colored plug going to this switch in the head but who knows there could have been a couple different manufacturers making these things back then for GM.. Plus it obviously had to be there if you observed it on some original, survivor cars...

Rich

[70LS6454]

Eric, great information as always,I learned something tonite.

Ray

[72-SS-L48]

I think Randy's comment (70 Forest Green) about the exterior condition of the carb was very interesting and Eric your response was great. I might be naive but I would imagine not too many people can take a carb all apart, rebuild it perfectly and put it back together maintaining the original "Survivor" look.

Eric the carb looks great, and you have such a talent for rebuilding / restoring these carbs. This thread is loaded with information. Thanks for the on-going education.

Tom - I can't wait to see your collection sometime soon.

-Dave