Product images and videos are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.
Advanced — 4+ hours
Overview
Show original supplier description
Part #: 0-80843HBX
Xtreme Performance - Holley Ultra XP (TM) carburetors! Ultra XP carbs are up to 38% lighter than our traditional race carbs, have fuel capacity that is 20% greater and 30 other new features! They're available in our all-new Hard Core Gray (TM) hard coat anodized finish with Black (TM) billet for improved corrosion protection. They're also available in natural tumble-polished aluminum with your choice of Black (TM) or Red (TM) metering blocks and base plate. The Aluminum Ultra XP comes in 600, 650, 750, 850, and True 950-CFM. Holley Ultra XP carburetors offer new features such as an integrated idle bypass valve that allows for idle adjustments while maintaining the correct throttle plate to transfer slot relationship, high capacity fuel bowls which feature 20% more fuel capacity to eliminate starvation, integrated fuel shelf to minimize fuel aeration and internal baffling to control fuel slosh. Other features include all aluminum construction, fully tunable billet metering blocks, billet base plate, adjustable secondary linkage and knurled (hand adjustable) curb idle screws. Holley Ultra XP carburetors are the ultimate in square bore race carburetors!
Features:
- Aluminum Construction (saves 4.5 lbs - 38% weight savings)
- Hard Core Gray with black anodized billet aluminum metering block and booster inserts
- Designed for use on Drag race, circle track, or any high horsepower engines
- E85 specific calibration
- Contoured venturri inlet offers balanced airflow for increased horsepower
- Air bleeds moved outward to allow a smoother transition of airflow from the top of the carburetor into the venturii
- Metering blocks feature improved durability, true gasket sealing and fully adjustable (emulsion bleeds, power valve channel restrictors & idle feed restrictors)
- Integrated idle bypass valve eliminates the need for holes in throttle plates and allows for proper adjustment of idle while maintaining correct throttle plate to transfer slot relationship. Helps maintain good idle control when using radical camshafts.
- Dual 30cc accelerator pumps provide the perfect amount of fuel from idle to full throttle
- Fuel bowls provide 20% more fuel capacity while controlling slosh with internal baffling
- Clear sight windows on both sides of bowls for easy and safe fuel level adjustments
- Built in drain plug in front center of bowl provides easy access to empty contents of bowl
- 8AN (o-ringed) inlet threads offer a large variety of plumbing options and can be plumbed from either side
- .130" stainless needle & seats to control the demand of E-85
- 4 corner idle allows you to precisely control your idle system
- Mechanical Secondaries for perfect off the line launches
- Elongated (dual pattern) mounting holes allow fitment on intakes with square flange (Holley 4150 (TM) style) or large flange (Holley Dominator (R) style)
- Knurled (hand adjustable) primary and secondary curb idle screws allow for easy idle adjustment without the use of tools
- Primary throttle shaft capped to prevent entry of debris & contaminates
- Factory machined accessory mounting hole for easy addition of adjustable primary throttle stop. New secondary pump cam lever designed to provide positive throttle stop on secondary side
- Stainless steel adjustable secondary link. Provides choice of 1:1 or progressivesecondary throttle actuation for ultimate control of secondary opening rate
- Baseplate designed with a boss that can be consumer machined for vacuum source
- Stainless steel throttle plates
- Includes notched float and jet extensions
- 100% wet-flow tested by Holley technicians to assure it arrives ready to run!
Mechanical Secondary Calibrated for E-85-4150
Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.
Fitment
Fitment Guaranteed
Don’t gamble
on fit.
Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.
Available on iOS & Android
Specifications
| Brand | Holley |
| Part Number | H00E 0-80843HBX |
| Weight | 7.85 lb |
Videos
We’re here — turning wrenches, just like you.
Call us, follow along, or come say hi.
Buy with Confidence
Returns & Fitment
Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.
View Full Return PolicyShipping
Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.
Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.
View Full Shipping Policy