7.4L Mercruiser exhaust manifold

[eastont]

I need to change the exhaust manifolds on my 7.4L Mercruiser inboard.

As I search the net for them I've found quite a few that say they are for my engine, but the prices vary up to $400.00

From ones that say salt water only to ones that are for fresh water only and of course ones that are good for both.

I want to change them over the winter so the boat will be ready early in the spring.

Can I use any manifold as long as it is for a 7.4L Mercruiser ?

Did I mention that I'm not that skilled as a mechanic ?

 

[Bt Doctur]

you don't list a year but the 2 types are standard and the newer dry joint type.
typically about 570.00 for kits like this that include 2 manifolds, 2 risers, mounting bolts and gaskets

 

[alldodge]

7.4L inboard
]Can I use any manifold as long as it is for a 7.4L Mercruiser ?

It's always good to know at least the year as BT mentioned of the motor, serial numbers are best.

That said all 7.4 manifolds should fit your motor, knowing the configuration will assist in ensuring other possible issues.

 

[eastont]

It's a 1989, sorry

 

[HT32BSX115]

you don't list a year but the 2 types are standard and the newer dry joint type.
typically about 570.00 for kits like this that include 2 manifolds, 2 risers, mounting bolts and gaskets

There's "Dryjoints" available for the 7.4L engines now? Where can I find'em?

 

[alldodge]

It's a 1989, sorry

Being an 89 all should fit, but there could be two variations with the elbows.

Appears to be an difference with the transmissions used, Borg Warner and Hurth. The Hurth had cast iron and stainless elbows, Borg just cast but also had a 3 inch diameter separation tube.

Could also use performance dry joint manifolds and elbows

 

[eastont]

It's a Borg Warner transmission,if that helps.

 

[alldodge]

It's a Borg Warner transmission,if that helps.

Then yours uses the tube (item 14) in link below originally. Also note the angle of the elbow (item 12), which can be 0, 15 or 7 degree angle. While zero degree is no longer available, others angles should be able to work with a slight mod, just hope you don't have the zero.

http://www.mercruiserparts.com/Show...=110&bdesc=EXHAUST+MANIFOLD+AND+EXHAUST+ELBOW

Look at your elbows and see what angle they point down