Best Square Body Ls Swap Parts: Headers, Mounts and Adapters

#1 · Best Overall

1. Certified Automotive Experts Long Tube Headers

• Weight: 20 lb

Best for: Square-body long-tube swap builder.

Why it ranks #1: Explicitly lists classic GM truck and Square Body fitment, 1-3/4-inch primaries, a 3-inch collector, MLS gaskets and header bolts.

Long-tube routing with 13⁄4-inch primaries and a formed 3-inch merge collector gives LS-swapped classic GM trucks a defined exhaust-header setup. Certified Automotive Experts lists fitment for 1960–1987 Chevy/GMC C10 and K10 trucks and 1988–1991 square-body trucks, with 2WD and 4WD applications identified.

The included MLS gaskets and 12-piece header-bolt kit put installation hardware alongside the two headers, helping keep those parts together for assembly. Long-tube routing and the 3-inch merge collector outlet specify the exhaust configuration, while the 13⁄4-inch primaries identify the tube size. The listing also includes a fitment and clearance video showing a test-truck installation, giving buyers a way to review setup and clearance details before choosing these headers for a listed truck.

Skip it if you need fitment outside the listed 1960–1987 C10/K10 or 1988–1991 square-body truck ranges; the stated coverage does not extend further.

For a builder fitting an LS into a listed classic GM truck, these long-tube headers bundle gaskets and bolts with defined collector dimensions. Check the stated truck-year range and review the clearance video against your installation needs.

Listed on Amazon as: LS Swap Long Tube Headers Polished 304 Stainless Steel for 1960–1987 Chevy GMC C10 K10 Trucks and 1988–1991 Square Body 2WD 4WD Includes MLS Gaskets 12pc Header Bolt Kit

#2 · Broad Year Range

2. Goopool Square Body Mounts

• Weight: 3.16 kg
• Dimensions: 10.7 x 5.3 x 5.2 in
• Material: Alloy Steel

Best for: Adjustable square-body engine placement.

Why it ranks #2: Lists 1973–1998 Square Body and OBS truck fitment, adjustable placement and compatibility with several common automatic transmissions.

Slotted adjustment lets these Goopool mounts change LS engine placement within the engine compartment, a practical aid when laying out a square-body or OBS conversion. The listing identifies 1973–1998 Chevy/GMC truck applications and names compatibility with several common automatic transmissions, including 4L60E, TH350, and 4L80.

The slotted brackets allow adjustment of engine position, giving a swap builder room to work through placement in the engine compartment. The stated transmission combinations include 4L60E, 4L65E, TH350, TH400, TH700R4, and 4L80, which helps buyers assess the mounts alongside their drivetrain plan. Compatibility is listed for LS-series engines and specified Vortec truck engines, while the truck range covers 1973–1998 square-body/OBS Chevy and GMC 2WD and 4WD applications.

Skip it if you need a listed kit of included components; daola888 LS Swap Motor Mounts explicitly list an alternator bracket as included.

These suit builders placing an LS or listed Vortec engine in a 1973–1998 Chevy/GMC truck who value adjustable positioning and transmission options. Match the truck and drivetrain to the specific compatibility details before planning the installation.

Listed on Amazon as: LS Swap Motor Mounts Compatible with 1973-1998 Square Body / OBS Chevy GMC Truck 2WD,4WD Adjustable Swap Engine Conversion Bracket for C10 C/K 1500

#3 · Adjustable Mounts

3. daola888 Square Body Mounts

• Weight: 2.4 lb
• Dimensions: 8.9 x 4.4 x 3.15 in
• Material: Alloy Steel

Best for: Adjustable OBS and square-body mounts.

Why it ranks #3: Designed for 1973–1998 Square Body and OBS trucks, with adjustable brackets and listed 2WD and 4WD compatibility.

Adjustable engine-conversion brackets let these daola888 mounts provide positioning flexibility for 1973–1998 Square Body and OBS Chevy/GMC truck swaps. The listing names C10 and C/K 1500 models among compatible applications and specifies alloy-steel construction, making the product’s truck range and adjustment its main selection points.

Adjustment gives a builder a way to position the engine during a conversion, while the stated 1973–1998 range identifies the square-body and OBS truck generations covered. The listing extends its application names to models including C10, C20, C1500, C2500, K1500, and K2500, helping buyers compare a specific truck to the stated scope. Alloy steel is the specified material, and the listed included component is an alternator bracket, which is relevant when organizing the swap parts.

Skip it if you need listed engine-family compatibility or transmission combinations; Goopool LS-ESM names both LS engines and transmissions.

For a builder working on a listed 1973–1998 Chevy/GMC truck, these mounts offer adjustable positioning and an explicitly listed alternator bracket. The supplied information names truck applications but not LS engine families, so check that distinction against your build.

Listed on Amazon as: LS Swap Motor Mounts for Square Body/OBS Truck.1973-1998 Black

#4

4. Ispeedytech Long Tube Headers

• Weight: 25.3 lb

Best for: C-series long-tube header selection.

Why it ranks #4: Its title specifies LS swap long-tube headers for Chevy and GMC C10 applications across a broad stated truck range.

Long-tube configuration is the clearest differentiator of these Ispeedytech headers, giving LS swap builders a specifically named exhaust-header style for Chevy and GMC trucks. The title lists C10 and C1500 applications from 1960–1998 and names LS1, LS2, LS3, LS6, and LS7 engines.

The long-tube description identifies the header style for builders planning an LS conversion, while the stated 1960–1998 range frames the listed C10 application. The title also names C1500, Silverado, and Sierra, along with five LS engine families, so buyers can compare their truck and engine against the product’s stated scope. The available specifications give a 25.3-pound item weight and package dimensions of 38 by 20 by 5.2 inches, useful details when planning handling and storage.

Skip it if you need a listing that specifies header material, included gaskets, or bolts; this listing identifies the long-tube style and truck applications.

These are an option for a builder whose truck and LS engine match the title’s listed applications and who is selecting long-tube headers. The stated scope centers on Chevy/GMC C-series models from 1960–1998, so use that boundary when evaluating fit.

Listed on Amazon as: LS Swap Long Tube Headers C10 for 60-98 Chevy GMC Silverado Sierra C10 C1500 LS1 LS2 LS3 LS6 LS7

#5 · Shorty Header Option

5. Certified Automotive Experts Shorty Headers

• Weight: 14.6 lb
• Material: Stainless Steel

Best for: Universal shorty-header swap projects.

Why it ranks #5: Lists Square Body truck applications and compatibility with 4.8L through 6.2L Gen III and Gen IV LS engines.

Shorty-style stainless-steel construction gives these Certified Automotive Experts headers a compact alternative to the brand’s long-tube option for LS swap projects. Listed applications include square-body trucks, OBS pickups, Blazers, Suburbans, and S10s, while the stated engine range covers Gen III and Gen IV LS motors from 1998–2020.

The shorty configuration distinguishes these headers from long-tube designs, while stainless-steel construction specifies their material. The listing covers 4.8L, 5.3L, 5.7L LS1, 6.0L, and 6.2L engines and names a broad range of swap vehicles, including 1973–1987 square-body trucks. That breadth makes them worth considering for varied swap builds, but the listing explicitly says they are for swaps only, not vehicles that came from the factory with an LS-style engine.

Skip it if you are replacing headers on a vehicle originally equipped with an LS-style engine; this listing explicitly excludes factory-LS vehicles.

Consider these for a swap builder seeking shorty headers for a listed LS engine and vehicle application. They are not intended for factory-LS vehicles, and the listing excludes LT-style engines from 2014 onward.

Listed on Amazon as: Stainless Steel Headers, Shorty Style for LS Swaps, Universal for Swaps Only, Not Designed to Fit Any Vehicle that came from Factory with an LS Style Engine

#6

6. AutoForge Shorty Headers

• Weight: 17.81 lb

Best for: Stainless shorty LS-swap headers.

Why it ranks #6: Lists 73–87 Square Body applications and compatibility with 4.8L, 5.3L, 5.7L, 6.0L and 6.2L LS engines.

Stainless-steel shorty headers give AutoForge’s universal LS-swap offering a defined material and compact header style for a broad set of listed swap vehicles. Applications include 1973–1987 square-body trucks, with engine compatibility stated for 4.8L through 6.2L Gen III and Gen IV LS motors.

Shorty style identifies the header configuration, while stainless steel specifies its material for buyers comparing exhaust parts. The listing names square-body C10, C20, C30, K10, K20, and K30 trucks, along with other swap vehicles, and covers several LS displacements from 4.8L to 6.2L. It also cautions that fitment may vary depending on setup. These headers are explicitly for LS swaps, not vehicles equipped with factory LS engines, a key boundary for selecting the application.

Skip it if you need headers for a vehicle originally equipped with a factory LS engine; these are specified for LS swaps only.

These fit a swap builder seeking stainless shorty headers for a listed square-body or other named vehicle and compatible LS engine. Because fitment may vary by setup and factory-LS vehicles are excluded, check those boundaries against the project.

Listed on Amazon as: Stainless Steel LS Swap Headers, Shorty Style, Universal for LS Swaps Only, Not Designed to Fit Vehicles with Factory LS Engines

#7

7. folosem LS Swap Mounts

• Dimensions: 0.2 x 0.1 x 0.2 in
• Material: Carbon Steel

Best for: Powder-coated carbon-steel mounts.

Why it ranks #7: Describes carbon-steel LS swap mounts with a protective powder coating, but its listed vehicle fitment is less clearly stated.

Carbon-steel construction with a protective powder coating is the defining feature of folosem’s LS swap mounts, with the listing citing resistance to rust and corrosion. Their stated application covers 1973–1998 Chevy/GMC 2WD and 4WD trucks, including C10 and C/K 1500 models.

The listing connects carbon steel and a protective powder coating with strength and resistance to rust and corrosion, useful considerations for a mount exposed to truck use. It states compatibility with Chevrolet LS-series engines and identifies 1973–1998 Chevy/GMC truck applications, including C10 and C/K 1500 types. Those details let buyers check both engine family and truck range before planning a conversion. The product is identified as a set of LS swap motor mounts, rather than an adapter plate for existing small-block mounts.

Skip it if you need compatibility checked against specific LS engine codes; Goopool LS-ESM lists individual LS and Vortec engine families.

These suit a builder seeking coated carbon-steel mounts for a listed 1973–1998 Chevy/GMC 2WD or 4WD truck. The listing describes LS-series compatibility broadly, so the stated information may not resolve a build requiring confirmation of a particular engine code.

Listed on Amazon as: LS Swap Motor Mounts for Square Body/Fuel Tank Chevrolet, Jimson, Chevrolet GMC Semi-Trailer 2WD, 4WD from 1973 to 1998, Ls Motor MountS are Applicable to C10 C/K 1500 Type Trucks

#8

8. ICT Billet Adapter Plates

• Weight: 2.1 lb
• Dimensions: 8 x 5 x 1 in
• Material: Aluminum

Best for: SBC-to-LS adapter plate conversion.

Why it ranks #8: Includes two billet-aluminum adapter plates and hardware for adapting an existing small-block vehicle mount to an LS engine.

These ICT Billet adapter plates let an LS engine mount to a vehicle’s existing small-block Chevy arrangement, targeting builders converting from SBC mounts. The plates raise the crankshaft centerline 0.17 inches and are made from 3/8-inch aerospace-grade, USA-produced billet aluminum.

Using existing small-block Chevy mounts gives these plates a distinct role in an SBC-to-LS conversion, rather than serving as truck-specific engine mounts. Their specified 0.17-inch crankshaft-centerline rise is a placement detail for planning the swap. The package includes two adapter plates, eight flat-head bolts, and six M10-1.5 flange bolts; the plates are M10 threaded, and the supplied hardware is specified for use with them. This makes the mounting approach and hardware package clear to the installer.

Skip it if you need truck-specific conversion mounts rather than plates for existing SBC mounts; daola888 LS Swap Motor Mounts list square-body and OBS truck fitment.

Choose these for an SBC-to-LS conversion where the vehicle’s existing small-block Chevy mounts are part of the plan. Their stated centerline change and included hardware help define the installation, but they are adapter plates rather than standalone truck mounts.

Listed on Amazon as: ICT Billet SBC Vehicle to LS Engine – Motor Mount Adapter Plate – Universal Swap Bracket Small Block LS Conversion Adjustable LS1 LS3 LS2 LQ4 LQ9 LS6 L92 L99 L33 LR4 Billet 551628

#9

9. Yoursme Adapter Plates

• Weight: 1.01 kg
• Material: Aluminum

Best for: Existing SBC mount adapter plates.

Why it ranks #9: Provides two aluminum small-block-to-LS adapter plates and hardware, but does not identify Square Body truck fitment.

Yoursme’s adapter plates let an LS-series engine bolt into a vehicle originally equipped with a small-block Chevy, using the vehicle’s existing mounts. The plates raise the crankshaft centerline 0.17 inches and include the specified bolts, making them a defined option for an SBC-to-LS conversion.

Using existing SBC mounts gives these plates a specific conversion workflow: they connect an LS engine to a vehicle that originally had a small-block Chevy. The stated 0.17-inch crankshaft-centerline rise provides a concrete placement consideration for the build. The listed package includes two adapter plates, eight flat-head bolts, and six M10-1.5 flange bolts, with the plates M10 threaded. Aluminum construction completes the material specification, while the named engine families include LS1, LS2, LS3, LQ4, and others.

Skip it if you need standalone mounts for a truck conversion rather than SBC-to-LS adapter plates; folosem LS Swap Motor Mounts list truck applications.

These suit builders converting an original small-block Chevy vehicle to an LS while retaining its existing mounts. The 0.17-inch centerline rise and included hardware are relevant planning details, but the product’s stated role is adapter plates, not standalone mounts.

Listed on Amazon as: for LS Swap Motor Mounts Adapter Plates – Universal Swap Bracket Small Block LS Conversion Adjustable Fit for LS1 LS3 LS2 LQ4 LQ9 LS6 L92 L99 L33 LR4 Billet Aluminum for SBC Vehicle to LS Engine

#10

10. Hooker G-Body Bracket

• Weight: 2.4 lb
• Dimensions: 6.75 x 5.38 x 2 in
• Material: Plastic

Best for: G-body crossmember add-on bracket.

Why it ranks #10: This is a G-Body crossmember add-on bracket, not a Square Body truck-specific LS swap part, so it is the weakest match.

An optimized engine and transmission inclination angle is the key function of Hooker’s G-body crossmember add-on bracket, with the listing tying that angle to suitable U-joint working angles. Its welded-steel construction and CAD modeling/FEA analysis address fitment and structural design for the stated G-body application.

The bracket’s stated purpose is to optimize engine and transmission inclination, helping establish suitable U-joint working angles in the intended G-body setup. Welded-steel construction and CAD modeling/FEA analysis are specified as part of its design, while the listing also identifies easy installation. These details make it a targeted crossmember add-on rather than a general square-body LS-swap mount. The title explicitly names G-body, so square-body truck builders should treat that application distinction as a key fit consideration.

Skip it if you need a bracket specifically listed for a square-body truck; this Hooker product is identified as a G-body crossmember add-on.

This is for a G-body builder addressing crossmember, drivetrain inclination, and U-joint working angles. Its stated application is G-body, so it is not a square-body-specific selection for a C10 or similar truck conversion.

Listed on Amazon as: Hooker G-Body Ls Swap Crossmember Add-On Bracket