I read the post and when they start talking bigger and better cams and the valve springs to go with it I will always think it is those things giving he horsepower increase rather than a bigger intake, especially on an marine or industrial engine. Seeing as how on a 390, going from the "S" manifold to the PI intake gains you no horsepower, as an example. I still don't by the SCJ intake making 20 horsepower especially with the port mismatch.

 

In the 1970's/1980's I used to sell these marine engines to peeps doing 460 conversions, and back then, they came with the same Holley 4V & manifold used on the 1973/79 F100/350's & Econolines.

Dealer net was $1600.00 / Retail was $2,000.00.

 

Prove it... That an "S" intake makes the same power as the PI! Like I said you can take it or leave it and do your own research on it. AND I didnt say it "Will make more power for your 390". Besides that "YOU" dont know what he has for heads. Maybe you should research that!!! What heads does he have??? so get over it. At least get part of the story right.

 

And the ones my Uncle worked on came with CJ Intakes from the factory!

 

In the Muscle Parts book Going from the "S" to the PI with the addition of the CJ 735 carb adds 17 horsepower. Just changing the carb also adds 17 horsepower. Hence the PI adds no horsepower without the bigger carb. The heads are the stock 390GT heads. You, by the way haven't proven that it is the SCJ manifold with the major port mismatch that makes the extra power on the Marine engine.

 

Reread the post : "CJ" intake and do your own research.

 

You claim total BS and make no attempt to even provide any cite for your claim and I have to do the research. My response to you is "Get hosed!"

 

You can suck a BIG FAT FATTY for all I care. As I told you My Uncle talked to one of the engineers at that time about it. Take it or leave it. I dont really care one way or another.

 

Second hand info is almost always incorrect or distorted at the very best, especially word of mouth.

 

All the 385 trivia aside, if it were the BEST way to go, we'd already be doing it.
Will it work? Yeah.
Is it the most effective for FEs? Don't think so.

 

Incase anyone wants to also read the 69 Muscle Parts Catalog it can be viewed online with other Ford performance catalogs at Ford casting ID numbers and part identification info for Mustang Shelby parts Just click on the library section. Covers 390-427-428 and the smallblocks too. Pretty interesting.

 

Different beasty A CJ/SCJ 385-series is different than a CJ/SCJ FE, and making blanket assumptions using one series to suggest something for another is, well, illogical to put it nicely.

Quote from the link you provided:

"The marine engines were equipped with: CJ-style cast iron intake; D3VE heads without drilled smog pump passages; different than normal valve springs, retainers, and had spring seat cups like Boss 351 or CJ. The hydraulic cam is much like the original SCJ camshaft;"

I guess the cam, springs, etc, has nothing to do with the increase.

Also, I see nothing about "worth 20HP". If the intake ports were matched, or smaller on the intake side, the flow WOULD be better, there's no disputing that.

If you are comparing marine to automotive, there is a lot more going on than just the different intake. AND, if you are talking "net" automotive HP, vs marine HP, that is also something else that's apples-and-oranges.

Going from a large intake port to a smaller head port is going to have atomized gas falling out of suspension as it slams into the head, and create a dam effect to the intake flow. I've never heard of it HELPING anything.

If you strap on a better intake, you might get better HP numbers even with the port mismatch, but just imagine what it will do without the port mismatch. And emissions will definitely suffer, as will MPGs.