Sierra 18-1908 MerCruiser Marine Boat Exhaust Riser Spacer Block 3″ 93320
By Sierra
PART #18-1908
WARRANTYLimited Lifetime
SHIPPING DIMS6" x 6" x 6"
$106.85 USD
Free Shipping to the Contiguous 48 US States
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Product Description
Sierra 18-1908 marine exhaust riser spacer block for MerCruiser center-rise exhaust systems from about 1985 through 2002. Replaces the 3 inch tall spacer that sits between the riser and manifold on many V6 and V8 applications. Does not come with gaskets, mounting hardware, or plugs. May require 3/4" and 1/8" pipe plugs depending on your configuration. Each purchase is for one spacer.

Riser mating bolt dimensions are 3-7/16" (87.3mm) by 3-1/16" (77.8mm) bolt center-to-center.

This part is new and high-quality cast iron construction. To determine if this is the correct replacement for you, look on your current part for casting numbers and match them to the cross reference below:

Cross ReferencePart Number
Osco Motors3320
Barr MarineMC-20-93320A3
Sierra Marine18-1908
Aqua Powern/a
GLM Products50300

About Sierra
Sierra provides premium-quality aftermarket replacements for over 6,000 marine parts, tools, and components. Sierra products are engineered to meet or exceed OEM standards, and stand up in harsh marine environments. Every new Sierra part comes with a limited lifetime warranty that covers the useful life of the product against any defects in workmanship and materials.
FitsMerCruiser V6 and V8 Center-rise
Item Weight6 lbs
Made InTaiwan
Manufacturer #18-1908
MaterialCast Iron
Part Number18-1908
Shipping Dims6" x 6" x 6"
Shipping Weight7 lbs
TypeExhaust Spacer Block
WarrantyLimited Lifetime