Description
This listing is for two (2) exhaust manifolds and two (2) 4″ 7° risers (elbows) for Mercruiser MODEL 330-370, V8 (B.B.), GM 454/502 CID (1981 up to 0M SN#’s) with raw/fresh water cooling systems without spacers. P/N (2) 51240 (GL51240)+(2) 51140 (GL51140); equivalent to the contents in GLM part number 58242 (GL58242.) **NOT FOR DRY JOINT EXHAUST** THE 4″ RISERS FIT 1981-early 2000’s. Note:Ordering this item will require a signature confirmation upon delivery. Please ship to an address where a signature can be obtained from UPS.
Imported customer feedback
What customers reported
3.6 / 5
25 ratings
Source: Amazon. These reviews were imported from the source marketplace and are not reviews of purchases made on this website.
Vehicle information
Available fitment details
Listing compatibility notes
- ) **NOT FOR DRY JOINT EXHAUST** THE 4" RISERS FIT 1981-early 2000's.
Fitment data is provided as a buying aid. Verify the listing against your vehicle and existing part before ordering.
Exact identity, part numbers, model references, and available compatibility evidence
Buying guidance
Quick decision
An identity-first manifolds listing organized around stable product references and available compatibility evidence.
Fit and size notes
- Verify the referenced part number: 58242.
- Match the complete identifier, side, position, connector, dimensions, and visible design with the existing part.
- Treat uncertain vehicle notes as a buying aid, not as a confirmed fitment guarantee.
Specification notes
- Canonical product: MP-US-B011J6IQE0
- Source product ID: B011J6IQE0
- Category: Replacement Parts / Exhaust & Emissions / Manifold & Parts / Manifolds
- Available images: 8
- Referenced part numbers: ['58242']
Before you buy
- Verify the referenced part number: 58242.
- Match the complete identifier, side, position, connector, dimensions, and visible design with the existing part.
- Treat uncertain vehicle notes as a buying aid, not as a confirmed fitment guarantee.
Customer –
Imported from Amazon. This is not a review of a purchase made on this website.
External marketplace context: Verified Purchase
Fit perfect !!!
Edward Kluska –
Imported from Amazon. This is not a review of a purchase made on this website.
External marketplace context: Verified Purchase
Fit as expected very pleased
Gambrelle –
Imported from Amazon. This is not a review of a purchase made on this website.
External marketplace context: Verified Purchase
Item was exactly as described. Fit perfectly in our 80s model Chris-Craft. Fast shipping
Verified buyer –
Imported from Amazon. This is not a review of a purchase made on this website.
External marketplace context: Verified Purchase
Worked well and very complete kit, thanks!
David arboleda –
Imported from Amazon. This is not a review of a purchase made on this website.
External marketplace context: Verified Purchase
One riser seal melted. It came defective. It had to be replaced by quicksilver. I had to hire mechanic again
Dan VanDerWoude –
Imported from Amazon. This is not a review of a purchase made on this website.
External marketplace context: Verified Purchase
Absolute garbage installed these on my boat in March 2021 totally rotted out and destroyed my engine by June 2023. Do yourself a favor and buy OEM mercrusier parts not this junk. One star because I couldn’t do 0 stars
chris m. –
Imported from Amazon. This is not a review of a purchase made on this website.
External marketplace context: Verified Purchase
These are for one side of the motor just look at the pictures,you have to put different fittings and hoses on to make it work
W_E_Coyote –
Imported from Amazon. This is not a review of a purchase made on this website.
External marketplace context: Verified Purchase
These are great quality but they should come with bolts. They require a different length bolt than the factory manifolds, which is a difficult surprise when you are trying to mount them because they weigh a ton.