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Moroso 21631 Flat Bottom Marine Oil Pan 10 Quart Full Sump with Crankshaft Scraper

(1968-1976 Oldsmobile 455 Big Block; 1977-1979 Oldsmobile 403 Small Block)

Manufacturer

Picture for manufacturer Moroso

Part Number

21631
5 reviews
Sale Price

$607.96

Estimated ship date Saturday, November 21

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Product Details

The Moroso 21631 Flat Bottom Marine Oil Pan is a high-performance oil pan engineered specifically for marine applications where reliable lubrication and consistent oil supply are critical. Featuring a full sump, 10-quart capacity design, this pan helps reduce oil temperatures while ensuring an adequate oil supply to the pickup area under demanding conditions.

Key Features:

  • 10-Quart Full Sump Capacity – Increased oil volume helps lower operating oil temperatures and extends engine protection
  • Built-In Crankshaft Scraper – Removes oil from the rotating assembly to reduce windage and improve horsepower
  • Trap Door Baffling – Prevents oil starvation during acceleration, cornering, and rough water conditions by keeping oil near the pickup at all times
  • Removable Sump Tray – Allows easy access to the bottom of the pan for thorough cleaning and maintenance
  • Flat Bottom Design – Purpose-built for marine use where hull clearance and a low-profile pan profile are required
  • Compatible with Most Starter/Flywheel Combinations – Offers broad fitment flexibility for a variety of marine engine setups

The Moroso 21631 is an ideal upgrade for performance marine engines that demand superior oil control, reduced thermal load, and reliable oil delivery under high-stress conditions. The combination of trap door baffling, crankshaft scraper, and full sump capacity makes this pan a complete lubrication management solution for serious marine builds.

Products specifications

Fits

1968-1976 Oldsmobile 455 Big Block; 1977-1979 Oldsmobile 403 Small Block

Baffled

Yes

Capacity

10 Quart

Color

Clear Zinc

Crank Scraper Included

Yes

Depth

7.25"

Dipstick Location

Driver side

Dipstick Provision

Yes

Drain Plug Thread Size

1/2-20 in.

Kicked Out

No

Maximum Stroke with OE Rod

4.000 in.

Notes

Oldsmobile engines used in hulls with flywheel aft and 4-point mounting

Oil Pan Capacity

10 quarts

Oil Pan Depth (in)

7.250 in.

Oil Pan Finish

Clear zinc

Oil Pan Material

Steel

Pickup Included

No

Quantity

Sold individually.

Rear Main Seal Style

2-piece

Stroker Clearanced

No

Sump Location

Full

Sump Style

Wet

so far so good

Very friendly customer service! They also shipped my radiator out very quickly. I will definetly be ordering from autoplicity again!

I needed a few small XRP fittings for our NHRA Top Alcohol Dragster, I had called XRP and even a "pro racer discount" the price was ridiculous; couple this with their ridiculous shipping/handling charge I had to go elsewhere. I typed in the XRP part number into Google and found Autoplicity, twice as many pcs. as I was planning on ordering and with shipping it was cheaper than one fitting from XRP direct. I will be checking Autoplicity anytime I'm ordering something from this day on, everything about the transaction was smooth and simple. I just got my tracking number today and the stuff is on its' way. Thanks for making this transaction so easy and not robbing your customers on something as frivolous as "handling".<br><br>Respectfully,<br>Brandon Booher<br>NHRA TAD #34

Ordered Thursday, shipped Monday... guess all in all we can't be disappointed. At least they had them in stock.

I build engines for Classic muscle cars and hot rods. Presently assembling chev. SB 383 cu/in. Went shopping for a Name Brand rotating assembly that was complete and ready to install.Shopped several other sites before finding "Autoplicity" Prices were GREAT (best I could find Anywhere), Shipping Very prompt, Shpg. charges Very reeasonable,I will Defenitely use them again!!!

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