I'm with Dog.
I've been running Holley carbs for over 35 years.
Double pumpers are for race cars or WTB racers.
Not the best selection for an offroader.
The vent tube is the thing with holes running from the front to rear of the carb.
The "Holley Off Road Truck Avenger" comes with one like that.
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You can do most of the tricks is the T/A carb on other 4160 Holley carbs.
This carb has the side hung floats, which are more desirable for off road use than the center hung floats, but the mods will work on either carb. My early mods were basically just to extend the vent tubes. I used straight 1/4″ copper tubing because it fit perfectly into the stock Holley vent tubes. I extended the vent tubes to within 1/2″ of the top of the air cleaner. Any closer than that and you may draw fuel vapor out of the vent tube thereby richening your fuel mixture. Next I played around with spring loaded needle seats. To me they did make a difference coming off big rocks or down staircases. My next mod was to install a vent whistle, While they are not recommended for side hung float bowls (model 4160’s) I modified it to fit. This is for the primary side only as the secondary side has a metering plate and the whistle won’t fit on the 4160 model carbs. I have had one in for close to 20 years with no problems. Basically you just cut the whistle down to about 1 1/2″-1 9/16″ then install in the metering block. Instead of using the rivet supplied with the whistle I staked the bottom of the metering block. Now it’s tight enough to hold the whistle in place and I can still remove it You can run a vent screen instead of the vent whistle if you like Holley P/N HLY-26-39 but I have never tried this. Next I bent the tubes in a arc & used fuel line to connect the tubes, but cut holes at the top of the curve. I have to shake my Jeep pretty hard to get fuel to slosh out. Just make sure you can still cruise down the highway with this lower setting, although with this new style vent tube the standard setting seems be good to go.
Now, that Holley started making a carb you run out of the box.
I just run the “Holley Off Road Truck Avenger” it’s pricey, but It’s been a great carb with very little adjustment has run great .
