454 Help
 

I have a '78 SRV20 that I recently bought back.

The first time I purchase the boat the PO had installed a rebuilt suburban 454 (along with some sandbags in the bow).

It would scream.

The guy that I sold it to - and eventually bought it back from put a 670 CFM dual inlet holley on it. NOT a marine carb.

I am now going back to a marine carb and considering a new intake (aluminum as present is cast).

I generally work on Early Broncos and know just enough about my boat to keep it running.

What CFM (generally) should I put back on the engine?

I have been looking at Holley 750-800 CFM models.

Thanks!

Gratuitous Bump!

I would almost bet your old engine had a Rochester quadrajet carb on it..I believe they were 795 cfm...so your 800 or 850 holley would be a good pick..or i think edlebrock makes a direct replacement for it...

edlebrock performer is a good intake and 750cfm will work just fine.

I have the edelbrock 750 marine carb on my 454 mag. It was awesome right out of the box. I replaced a holley 800 double pumper with it and I'm not going back. I also put a 600 edelbrock on my older boat and I got 250 rpm back from the previous carb. Good luck on your project.

Not long ago I had my engines rebuilt/upgraded. Started as 330 hp and went to 470 hp. Used 750 marine edelbrock's. Worried that that was not enough cfm but after dyno runs it showed it was enough. Have 40 hrs on them now with no problems. Bolted them to stock Mercruiser square port alum. intakes.