New carb for 302 Mercruiser?

conk3416

Petty Officer 3rd Class
Joined
Jul 25, 2009
Messages
76
I currently have the stock carb for my mid 70's 302 Mercruiser motor. Its a 2 barrell holley and i believe it is 300 cfm. I would like to get a carb that is around 500 cfm. Is this a good idea? what would be the best carb to get? 2 brl or 4 brl?

Thanks, Andrew
 

zbnutcase

Commander
Joined
Sep 19, 2009
Messages
2,055
Re: New carb for 302 Mercruiser?

Switch to a 4bbl manifold and use Edelbrock 1409 marine carb.
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Re: New carb for 302 Mercruiser?

Howdy,


Is there something wrong with the current carb you have?

Go to Holley Tech Support http://www.holley.com/TechService/Library.asp and have a look at the Carb Numerical Listing

There, you can look up your specific carb for the correct CFM rating etc.

Changing to a larger cfm 4bbl probably won't make a noticeable difference.

If your carb is defective, you can have it rebuilt (if you cannot do it yourself) by sending it to Flyingfish carburetors or other carb rebuild place and they'll either rebuild yours or send you a "reman".


Regards,


Rick
 

conk3416

Petty Officer 3rd Class
Joined
Jul 25, 2009
Messages
76
Re: New carb for 302 Mercruiser?

is it ok to put a 4 barrel carb on a 2 barrel intake with an adapter plate?
 

a70eliminator

Captain
Joined
Sep 9, 2007
Messages
3,762
Re: New carb for 302 Mercruiser?

It works but no performance gain and linkages will not fit comfortably being set up higher.
 

haulnazz15

Captain
Joined
Mar 9, 2009
Messages
3,720
Re: New carb for 302 Mercruiser?

Not worth your time to do a 4bbl carb with a 2bbl intake. A dual plane intake will add about as much power as the carb will and allow you to get much better air/fuel mixture.
 
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