Best 5.7 Marine Exhaust Manifold Replacements for MerCruiser V8 Engines
Direct answer: these 5.7 marine exhaust manifold options are selected for MerCruiser small-block V8 engines (5.0L/5.7L), offering suitable replacements with compatible cross-refs, risers, and wet-joint designs. Best for boaters seeking reliable, cost-effective manifolds that fit 1983–early 2000s MerCruiser powertrains. This guide notes who each product is best for, plus a quick comparison table to help you decide.
| Product | Brand | Best For |
|---|---|---|
| A-Premium Marine Exhaust Manifold with Hardware Kits | A-Premium | MerCruiser MCM/MIE 5.0L-5.7L-377 CID; replacement for older MerCruiser builds |
| FASWORX Exhaust Manifold & Riser Kit (MerCruiser 5.0/5.7/6.2) | FASWORX | Wet Joint, center-rise systems; 1983–early 2002 |
| 2PCS Marine Exhaust Manifold Replacement (Weonefit) | Weonefit | MerCruiser GM V8 305/350/377 CID; 1983–2002 |
| FASWORX Exhaust Manifold & Riser Kit – Volvo Penta 5.0/5.7 | FASWORX | Volvo Penta/OMC setups; tall risers; 1992+ |
| FASWORX Exhaust Manifold for MerCruiser 5.0/5.7/6.2 | FASWORX | MerCruiser small-block V8; 1983–early 2002; robust seal, cross-reference |
A-Premium Marine Exhaust Manifold With Hardware Kits
Best for MerCruiser (MCM/MIE) GM V8 engines including 5.0L, 5.7L, 305, 350, 377 CID (1983–2002). This manifold kit references multiple part numbers to align with OEM cross-refs and includes hardware for a complete replacement. It emphasizes a copolymer intake manifold, offering corrosion resistance and longevity, reducing wear and noise over time. The kit’s flexible design helps address potential blade wear or rust issues.
Who it’s best for: boat owners needing a direct replacement that aligns with MerCruiser cross-refs and values long-term durability. Caution: verify compatibility with your specific engine serial and the exact MerCruiser model to avoid mis-match with rare builds.
FASWORX Exhaust Manifold & Riser Kit for MerCruiser
Best for MerCruiser 5.0L (305), 5.7L (350), 6.2L (377) V8 engines with a Wet Joint 4” center-rise system (1983–early 2002). This kit provides OEM cross-reference compatibility (860246A15, 860246Q11, etc.) and includes risers/elbows with corrosion-resistant parts. It’s a strong pick when you need reliable replacements that align with multiple MerCruiser part numbers.
Best for: boaters who want a single kit replacement that covers manifold and riser needs with aftermarket cross-references. Limitation: ensure your exhaust system uses a 4″ center-rise wet joint configuration to avoid fit issues.
Weonefit 2PCS Marine Exhaust Manifold Replacement
Best for MerCruiser GM V8 305/350/377 CID engines from the early 1980s to 2002. It lists multiple part numbers (860246A10, 860246A15, 860246Q11, etc.) and notes compatibility with MCM/MIE engines. This option is suitable for owners replacing both manifolds at once for balanced cooling and exhaust flow.
Choose this if: you want two manifolds with broad cross-reference coverage. Caution: verify the exact part numbers for your engine before purchase to ensure full compatibility.
FASWORX Volvo Penta Exhaust Manifold & Riser Kit
Best for Volvo Penta 5.0L/5.7L engines (1992+), OMC/Volvo Penta setups requiring a tall elbow with drain features and a 7.75″ riser dimension. The kit includes gaskets, bolts, and plugs, with cross-reference coverage to match several OEM numbers. It’s a good pick when upgrading a Volvo Penta/OMC system to improve cooling and reliability.
Limitation: measure your riser height before purchase to ensure the 7.75″ tall elbow matches your engine bay space and existing components.
FASWORX Exhaust Manifold for MerCruiser 5.0/5.7/6.2
Best for MerCruiser small-block V8 engines (5.0L, 5.7L, 6.2L) with wet joint center-rise systems (1983–early 2002). It emphasizes leak protection with machined flat mating surfaces and premium graphite gaskets. The kit directly replaces several OEM cross-referenced part numbers and aims to improve efficiency and seal integrity.
Choose this if you want 100% machined surfaces and high-quality gaskets for a reliable seal. Limitation: ensure your engine uses a wet joint center-rise configuration to avoid mismatches.
FASWORX Exhaust Manifold Set for MERCRUISER 5.0/5.7 (No Spacer Block)
Best for MerCruiser 5.0 (305) and 5.7 (350) engines, 1983–2001. This no-spacer-block set mirrors factory parts while providing affordable aftermarket alternatives, with a focus on compatibility across multiple OEM references (87114, 860246 series, etc.). It is suitable for users who want a straightforward swap without spacers.
Limitation: this kit specifies no spacer block; confirm your current exhaust layout to ensure proper fitment with your riser and elbow configuration.
Buying Guide
What engine and system do you have?
Most 5.7L MerCruiser builds use wet-joint, center-rise exhaust with 4″ hose outlets. Confirm your engine displacement (5.0L, 5.7L, or 6.2L) and whether your vessel uses a MerCruiser MCM/MIE installation to pick the best cross-reference.
Risers, elbows, and height considerations
Some kits include tall elbows (e.g., 7.75″ risers) or specific riser heights. Measure your current risers and ensure the new set matches your boat’s clearance, mounting points, and hose connections. A mismatch can cause water flow restrictions or installation challenges.
Cross-reference coverage
Look for parts that list OEM cross-references (e.g., 860246A15, 8860246A15, 87114A19, etc.). Cross-reference coverage reduces the risk of buying a part that won’t fit your engine’s serial or model year.
Materials and seal integrity
Manifolds with machined mating surfaces and compatible gaskets resist leaks under heat cycles. Premium graphite or stainless gaskets help prevent exhaust leaks and boost longevity in saltwater environments.
Warranty, install ease, and hardware
Consider whether the kit includes gaskets, bolts, and plugs. A complete hardware-inclusive kit simplifies installation and reduces the chance of missing components during replacement.
Which one should you choose?
- Best overall MerCruiser compatibility: A-Premium or FASWORX kit with extensive OEM cross-refs and hardware.
- Best for two-man replacement jobs: Weonefit 2PCS set, if you want matched pair manifolds quickly.
- Best for Volvo Penta users: FASWORX Volvo Penta kit with tall risers and drain features.
Practical quick-check questions
- Is my engine a MerCruiser MCM/MIE 5.0L or 5.7L V8? If yes, these options fit well.
- Do I need a center-rise wet-joint configuration with a 4″ outlet? If so, verify the kit’s compatibility.
- Do I require hardware and gaskets included? If yes, prefer a kit including seals and bolts.
- What is my riser height and do I need a tall elbow? Measure to avoid clearance issues.
FAQ
Will these manifolds fit all 5.7 MerCruiser engines?
They cover many 5.0L and 5.7L MerCruiser V8 builds from the 1980s through early 2000s along with cross-reference compatibility. Verify your exact part numbers and engine year for a precise fit.
Do these sets include gaskets and bolts?
Some kits include hardware and gaskets, others specify separately. Check each product’s features to confirm included components.
Are wet-joint center-rise configurations required?
Yes, these options are designed for wet-joint center-rise exhaust systems with 4″ outlets in the specified years.
Can I mix brands for manifolds and risers?
Mixing brands can introduce fitment issues due to tolerances. It’s best to use a matched kit or confirm compatibility with cross-reference data.
What should I do if I’m unsure about fitment?
Consult the OEM cross-reference numbers listed by the kit and compare with your engine’s part numbers. When in doubt, contact the seller for confirmation before purchase.