Carb-to-EFI Conversion Kits (SBC first)

Swapping a carburetor for EFI is not one product - it is a throttle body (or a whole new manifold), a high-pressure fuel system, and a box of supporting parts, and kits differ in how much of that they actually include. This page pulls together the conversion systems we currently have in stock - 24 kits from FiTech, Holley Sniper EFI, Edelbrock, MSD, Aces Fuel Injection and Holley EFI, from $893.32 to $2,626.63 - led by the small-block Chevy applications, with every kit on the page a square-bore system. Every kit listed is in stock and ready to ship, and every order over $200 ships free.

OUR CARB-TO-EFI PICKS

Kit	System type (from the product listing)	Key spec (from the product listing)	Price	Why it is here
Go Street EFI 400hp Kit Cast Finish	Throttle body, square bore	80 lb/hr injectors; 400 hp kit rating in the listing title	$893.32	The floor of this page’s ladder: FiTech’s Go Street throttle-body system in cast finish, square bore with 80 lb/hr injectors, for a mild small-block swap that does not need a big rating.
Sniper 2 EFI Kit Black	Throttle body, square bore	Sniper 2 EFI, black; base system (no PDM in this kit name)	$1,449.95	The mainstream Sniper 2 pick: Holley’s current-generation throttle-body system in black, and the deepest-stocked kit on this page when this page was built.
SBC Ultra Ram EFI System	Multi-port, SBC-specific	36 lb/hr injectors, 92 mm throttle body	$1,834.00	The SBC-specific multi-port option: FiTech’s Ultra Ram is built for Small Block Chevy - a port system, not a carb-shaped throttle body - with 36 lb/hr injectors and a 92 mm throttle body in its listing.
Sniper 2 EFI Bundle Kit SBC BLACK	Throttle body, square bore, SBC bundle	Listing names computer / distributor / fuel pump / regulator / fittings / ignition coil / wiring	$2,499.95	The SBC bundle: this Sniper 2 kit’s listing names the fuel pump, regulator, fittings, distributor and ignition coil in the box - the parts base kits leave you to source. Built for Small Block Chevy.
Pro-Flo 4 EFI Kit SBC 550 HP	Multi-port, sequential, SBC	35 lb/hr injectors, 1000 CFM, distributor listed; 550 hp kit rating	$2,617.49	The top of this page’s ladder: Edelbrock’s Pro-Flo 4 for Small Block Chevy - sequential multi-port with an injector per cylinder, 35 lb/hr injectors and a distributor in the listing.

START WITH THE FLANGE, THEN THE HORSEPOWER RATING

Every kit on this page is a square-bore system - the 4150-style flange pattern named in the listings - because that is the manifold the classic small-block swap starts from. If your car still runs a spread-bore Quadrajet carburetor or a 2-barrel, a square-bore kit is not a bolt-on answer for it: those flange-specific Sniper variants live in the wider fuel-injection range linked at the bottom of this page, or the manifold changes first. Once the flange matches, size by the rating in the kit’s own name, not by the CFM of the carburetor coming off - these systems are not sold on a CFM equivalence. The FiTech throttle-body line on this page is rated in its titles at 400 hp (Go Street), 600 hp (Easy Street and Go EFI 4), 800 hp (Mean Street) and 1200 hp (Go EFI 8, which also lists nitrous control), and Edelbrock’s Pro-Flo 4 SBC kits are rated at 550 hp. Those numbers are the makers’ ceilings for the kit, not a promise of what a given engine will make - pick the ceiling with headroom over your engine, and remember the fuel pump has to support the same number.

THROTTLE BODY OR MULTI-PORT?

Most of this page is throttle-body injection: a carb-shaped unit on your existing square-bore manifold, fuel introduced at the throttle body. FiTech’s Go Street / Easy Street / Go EFI and Mean Street systems, Holley’s Sniper and Sniper 2 lines, Edelbrock’s EZ Street (4150 flange, computer and wiring harness named in its listing), MSD’s Atomic master kit, Aces’ Killshot 2 ProMaster (built for Chevy V8, with computer, distributor, fittings, ignition coil and wiring harness named in its listing) and Holley’s Terminator X Stealth 4150 are all built that way. The step up is multi-port: one injector per cylinder on a manifold built for it. On this page that is Edelbrock’s Pro-Flo 4 SBC kits - listed as multi-port, sequential, with a distributor in the kit - in standard SBC (two injector sizes: 29 lb/hr in the 35760 kit, 35 lb/hr in the 35770) and a Vortec-head version (35780), plus FiTech’s SBC Ultra Ram (multi-port, 36 lb/hr injectors, 92 mm throttle body). Multi-port costs more and changes more parts; throttle body is the simpler swap that keeps your manifold. Neither is automatically right - it is a budget and build-goal decision.

BASE KIT, MASTER KIT, BUNDLE - READ WHAT IS IN THE BOX

Kit names are doing real work on this page, so read them literally. A base kit - Holley’s Sniper 2 Base Kit is the clear example, sold “without PDM” - is the system itself, and its listing does not name a fuel pump. A master kit adds the fuel side: FiTech’s Go Street Master Kit, Holley’s Sniper Stealth 4150 Master Kit, and MSD’s Atomic Master Kit, whose title says the quiet part out loud - “w/Fuel Pump.” Holley’s SBC bundle kits go furthest in their listings: the BPX bundle names computer, distributor, ignition coil and wiring, and the BPK bundle adds fuel pump, fuel pressure regulator and fittings to that list. The honest rule: an EFI system runs on high-pressure fuel delivery that a carburetor’s low-pressure mechanical pump does not provide, so if the listing for the kit you are eyeing does not name a pump, budget for the fuel system separately - it is part of the conversion price, not an accessory.

SMALL-BLOCK CHEVY FIRST

The slate for this page leads with the SBC because the catalog does: Holley sells Sniper 2 kits built and named for Small Block Chevy - the BPX and BPK bundles above, a kit with PDM and SBC ignition, a 5-inch-touchscreen PDM kit with SBC ignition, and a master kit with SBC ignition - alongside the universal Sniper 2 and Stealth 4150 systems any square-bore V8 can use. Edelbrock’s Pro-Flo 4 line is engine-specific by design, and its SBC and SBC Vortec kits are the multi-port ceiling here. FiTech covers the SBC two ways: the universal square-bore throttle-body systems, and the Ultra Ram system built for Small Block Chevy specifically. Aces’ Killshot 2 ProMaster is listed for Chevy V8. If your engine is not a small-block Chevy, the universal throttle-body kits on this page are still the starting point - read the individual listing’s fitment note and check the manufacturer’s application guide for your engine before ordering, because “universal” describes the flange, not a guarantee for every engine.

QUESTIONS SBC OWNERS ASK US

Does the kit include everything I need to run? Only the master and bundle kits come close, and even then you should read the individual listing’s contents list before ordering. Base kits on this page do not name a fuel pump in their listings, and an EFI conversion needs a high-pressure fuel pump, EFI-rated lines and filtration, and an oxygen sensor installed in the exhaust for the system to self-tune from. If you are comparing a base kit against a master kit on price, compare them again after adding the fuel system the base kit still needs.

Will one of these kits control my ignition timing - or my automatic transmission? It depends on the kit, and the listings here are the authority: the SBC ignition bundles and the Aces Killshot kit name a distributor and ignition coil in the box, and Edelbrock’s Pro-Flo 4 listings name a distributor. None of the 24 listings on this page states electronic transmission control, so if your car runs an electronically controlled automatic, treat that as a separate question - call us at 213-549-4279 (Mon-Fri, 9am-5pm PT) before ordering and we will work through what your combination needs.

Is an EFI conversion legal on my street car? Check the listing for the exact kit: Holley’s Sniper listings on this page carry a California emissions notice stating the product is not legal for sale or use in California on pollution-controlled motor vehicles. Rules vary by state and by vehicle, and this page makes no emissions-legality claim for any kit - if legality matters for your car, settle it against the manufacturer’s notice for the exact part number before you order.

Can I install this myself? The listings for these systems state that professional installation is recommended, and we echo that: the swap combines fuel plumbing, wiring and exhaust work, and the system can only self-tune correctly on a correct installation - right fuel pressure, no exhaust leaks ahead of the oxygen sensor, and sound grounds. If you are planning the job, lay the whole parts list out first (kit, fuel system, fittings, sensor) so the car is apart once, not twice.

Shopping the wider range? Browse the full Electronic Fuel Injection Systems collection, read our guides on the News & Builds blog, or see the page that came before this one: GM Platform Coilovers (A/G/F-Body).

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