New exhaust manifold and riser kit for MerCruiser V6 marine gas engines (GM/Chevrolet 4.3L 262 cu. in.). Fits engine years 1985 to 2002 that used 4-inch outlet cast iron risers. Accepts all factory accessories. Kit includes 2 manifolds, 2 risers, 2 lower water fittings, 8 riser bolts, and all plugs and gaskets (including two spare riser gaskets). Each purchase is for one engine kit. Manifold-to-head bolts are sold separately (see my grade-8 bolt sets here).

This kit does not replace newer Mercury "dry-joint" style exhaust or exhaust systems that use stainless steel risers or 3-inch outlet risers (measure on the I.D. of the hose). If you have MerCruiser "one-piece" manifolds, see my conversion kit.

This kit is new, high-quality cast iron construction, and is made in the USA. Sierra Warranty Information. For tips on replacing exhaust manifolds and risers, see my eBay guide. To determine if this is the correct replacement for you, look on your current manifolds and risers for casting numbers and match them to the cross-reference below:

Cross Reference	Part Number
MerCruiser	Manifold:  Riser:	99745, 99746, 99746A8, 99746A17 44354, 44354A3, 44354A9, 44354A10, 44354A13 807988, 807988A2, 807988A3, 807914A1
Osco Motors	Manifold:  Riser:	9745 4354
Barr Marine	Manifold:  Riser:	MC-1-99746 MC-20-44354
Sierra Marine	Manifold:  Riser:	18-1952-1 18-1976-1
Aqua Power	Manifold:  Riser:	5505 5706
GLM Products	Manifold:  Riser: Kit:	51220 51140 58222

This item has a Limited lifetime warranty covering any manufacturer defects. Defective items are generally replaced within a few business days, plus time in transit, and there will never be any extra cost to you.

Lost Items, Damage, or Other Problems
If your item has a problem, such as being delayed, lost, or damaged by the shipping company, or if there are missing components, please send an eBay Message or Email right away describing the nature of the problem and its urgency (include pictures if possible). Everything will be done to assist you in a timely manner and there will never be any additional cost to you.

Regular Returns
You may return an item if you no longer need it or don't want it anymore. Returns are accepted on items still in the same condition they arrived in. There may be a 15% restocking fee and all shipping costs must be covered by the buyer. To initiate a return, log in to eBay, go to your "Purchase History", and use the "Return" link next to the transaction.

Q: Does this include both starboard and port side manifolds and risers?
Yes. Each kit is enough to do one engine.

Q: What sealant should I use on the plugs?
Use a Permatex non-hardening sealant. Avoid using a Teflon or tape product, as they cannot handle the heat as well.

Q: What should I torque the bolts to?
It depends on the grade of bolt and thread size. Use thebelow chart to determine the torque rating you shoulduse:


Q: How does the quality compare to other brands?
These manifolds and risers will meet or exceed the quality of the original factory parts. They are manufactured in the USA and come with high-quality, thick composite gaskets (not thin paper).

Q: Who manufactures this item?
This item is manufactured by Sierra.

Q. What are the shipping dimensions and weight?
This item ships in a box approximately 20" x 18" x 16" and weighs approximately 124 lbs.