HawkX66

I just picked up a 29' Sea Ray with a 454ci/7.4L in it. Carbed. It needs a new intake, but before I buy one, I had a couple of questions. Do I want to go with the factory cast iron one for $531 from the boat yard it's stored at or do I want to upgrade to aluminum? This boat will see some salt water time so I was thinking it would be smart for performance as well as corrosion resistance to go with a nice aluminum instead of the factory set up. I'm also going to put a new water/circulating pump on it at the same time.
I just built a Gen VI 454 for my 69 Camaro, so I'm pretty familiar with the platform. Just not on the marine side.

Thanks for any advice.

SB

This maybe the same cast iron intake as what merc uses. Double check before you buy, if you are going to buy. Note: GMPP isGM Performance Parts which there are many chevy dealerships that are part of this. Yoo may have one nearby if that matters to you.

https://paceperformance.com/i-625541...et-flange.html

HawkX66

Price is definitely much better, but I thought marine intakes flowed differently than auto intakes? That looks like a regular car BBC intake. Am I off in my thinking?

F-2 Speedy

The one SB posted is for a marine app, see the 4 additional bolt holes, auto wont have them

SB

Then post up what your intake looks like and if it's oval or small oval or what have you and then we'll see.

HawkX66

I don't have it handy to take a pic, but it's just a stock Mercruiser BBC intake.
Which four bolt holes are you talking about? Mounting holes would be the same wouldn't they? What I'm concerned with is also the flow characteristics. A boat is "always driving uphill" unlike a car so the intake flows differently.
Also, my other question really is about aluminum performance intake versus cast iron.

Thanks.

Helmwurst

Flows the same as a car intake. Difference is most GM intakes have a brass seal around the water ports. Depending on the model number and serial number of your engine, will determine the right original style intake. The picture does not show the 4 holes, but what he is referring to is there are 4 extra holes on the carb mounting flange for the 2 different bolt pattern carbs used, Quad spread bore and Weber square bore.

HawkX66

Ok. Quadrajet or Holley 4150 mount style. Really nothing to do with marine application or not. Thanks.
If I can run a car intake, I might as well run one of my intakes that I already have. Cast iron also only has the quadrajet bores.
So riddle me this... Why would someone want to spend $500+ on a cast iron intake when they can run something like an Edelbrock dual plane low rise that will flow much better and produce a better torque curve?

https://www.summitracing.com/parts/edl-7561/make/chevrolet

GETTINBYE

There are many parts that are the same - marine vs automotive. Marine dealer $$$$$. Automotive dealer $-$$.

Helmwurst

The Edelbrock Performer RPM Air-Gap or the Weiand Stealth are both pretty good intakes. The next restriction is the factory exhaust.