Non Responsive Holley VS Carburetors

[1980RS]

Over the years I have shied away from Holley and other brands of vacuum secondary carbs as they work like s**t. This week after watching a few videos I know know why the bigger cfm VS don't work well or the sec side will not open. Holley omitted the brass tube in the pri side that gets the pod to open up. I have a 750HP VS that no matter what I tried it was the slowest carb next to my Demon VS and it was a real stone. Today I added the little brass tube with a 45° tip into the pri side and went to the dyno to test it and one without the tube. Sure has heck the HP with the tube worked perfectly while the other Holley barely would open. The 3310 we tested worked perfect also. I for the life of me cannot figure out why Holley would not put that tube in there anymore. I know a few guys with Avenger 770's say their cars are just gutless turds with it. Just thought I would share the info getting something you pay good money for and it did not work right out of the box.

[BOOT]

Think I have a very old junky holley on a shelf with that tube got a pic?

[Brambles]

I just ordered a Quick Fuel SS 780 VS...hopefully not the same issues with that carb...

[Tuner]

I can't quite remember, where have I heard that before?

https://www.tapatalk.com/groups/racingf ... -t205.html

[F-BIRD'88]

The aftermarket Holley 750 vs carbs were cheap junk in that way and many other internal ways compared to the 60's 70's era OEM muscle car 750vs versions of these. Like night and day.
The missing tube in the Vac pick up port in the venturii is just one.

[bobmc]

do FST carbs have this issue?

[BOOT]

The aftermarket Holley 750 vs carbs were cheap junk in that way and many other internal ways compared to the 60's 70's era OEM muscle car 750vs versions of these. Like night and day.
The missing tube in the Vac pick up port in the venturii is just one.

Played with a used 750 VS many many years ago before I went MS and not messed with VS since but been meaning to give one another shot. What other mods?

[F-BIRD'88]

Everything except the fuel bowls and the screws get changed or tweeked.. Don't even bother starting with a 3310-2 -3 ... etc unless you need the fuel bowls.
You can buy all the components in a kit or buy a aftermarket carb that has it all already.
I could fill pages on modding VS carbs but CamKing will probabily get all in a knot ,again.

[1980RS]

do FST carbs have this issue?

When I tested my 850 FST VS it would not open. Before I add the tube I am going to test it out on the car, I will add the paper clip to see if it opens that's how I found my 750 HP was not opening at all.

[novadude]

Everything except the fuel bowls and the screws get changed or tweeked.. Don't even bother starting with a 3310-2 -3 ... etc unless you need the fuel bowls.
You can buy all the components in a kit or buy a aftermarket carb that has it all already.
I could fill pages on modding VS carbs but CamKing will probabily get all in a knot ,again.

The '3310-2' carbs aren't bad. They have straight leg boosters and are 4160 vs 4150 style, but everything else is the same as the earlier carbs. The "dash 2" was the last to include the signal tube we are discussing here.

[thedynoguy]

I just ordered a Quick Fuel SS 780 VS...hopefully not the same issues with that carb...

The QFT (and now Brawler) VS carbs do NOT have the same problem. The secondary opening action is tunable with the needle screw on the side of the vacuum can.

[jmarkaudio]

do FST carbs have this issue?

The two I reworked needed a bit of work. Brand new out of the box. The signal tube wasn't a mod I made, but my suggestion is stick with a Holley or Quick Fuel.

[1980RS]

do FST carbs have this issue?

The two I reworked needed a bit of work. Brand new out of the box. The signal tube wasn't a mod I made, but my suggestion is stick with a Holley or Quick Fuel.

From what I have read you are the man when it comes to carburetor repairs and making the super nice 4150 carbs with the BLP main bodies. They look like a work of art.

[clueless]

I build quite a few 750VS carbs for street cars. Start with a 3310 of any vintage, replace the body with the Proform unit (which has the primary only referenced vac tube) and fit a secondary block for ease of jetting change.

They always drive great and rip tyre, especially on something with less than about 4K of stall.