Thread: Best intake for existing 390 combo

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Nubie here, recent owner of a 69 mach 1 with a 390, .30 over with a 428 crank (told this is called a 410). I have a Holley 790 and long tube headers. The current Offenhouser intake is leaking like crazy and I suspect could be warped. I would like to know if anyone has a replacement intake recommendation. I am looking at the Eddelbrock 2105, supposed to be designed for the 0-5000 rpm tourque range of this motor. Any and all help is very much welcomed. Mike

That would be a good intake, if it matches your normal operating rpm for the car. Should be about right for a 410...what carb is on it??? Do you have the list number off the carb? Not sure what a Holley 790 would be....

I just had the carb at a very respected shop in Costa Mesa. I thaught it was a 780 but was told it is 790. I will be pulling it apart in about a week to check the offy intake with a straight edge. In the mean time I have looked around the forum and found some references to "cork gaskets" ? I am not a mechanic, weekender at best. Long time GM guy new to the Ford world. thanks for your help!

Probably the old standard 3310 Holley, it is 780 CFM far as I know.

Could be a number of issues.... a warped intake is possible, but not too likely. The FE's are not the easiest engine made to swap intakes on, so I would also be checking to see if one or both of the intake gaskets have slipped.... Not knowing any history on the engine also puts you at something of a disadvantage.... Also possible that the heads have been milled and is causing a misalignment problem on the intake. Should be fairly easy to determine the cause of the vacuum leak once you get it apart...

Dave, you are correct, I checked with the Carb Shop and it is a 780, my mistake. BTW my last Holley was a 650 on a 68 Firebird 22 years ago! The current manifold is an aluminum Offy, not sure if it is a proper application for this torque monster. I am almost afraid to get it running right, it just wants to go FAST!!!!! Thanks for your input.
Mike

The Offy--probably a Port-o-sonic(?) is a good intake on the FE's... Weiand used to make a very nice dual plane intake for the FE's, flowed great for a street intake and built some very good low and mid-range torque.... Can't remember the name or number off the top of my head, try to look it up somewhere. I know I put a note about it in one of my books.......If G comes around, he'll know the one I'm talking about, and he has a functional memory!!!!! Curious to see what the source of your leak is when you get it apart....

saw this on good ol ebay. but run a search on ebay for fe intakes or 390 intakes as theres a few on there for sale. best of luck! http://cgi.ebay.com/ebaymotors/Ford-...spagenameZWDVW

Yep Dave that's the Weiand 7282 and the same in the ebay ad outsider posted. LOL Weiand used to list the intake as a high-rise.... but looks more like a pancake.

Yup, that's the one. It's been out for years, but makes some real good power for a dual plane intake, about the best I've tried on street FE's...

Thanks for the info, when I get it pulled apart I will look into this OFFY. Like I said, this car is a torque monster, just waiting to get it running right.
Mike

Hi Mike, my names Mike. What else have you done to that engine? Comp ratio, stroker, heads, headers? Just trying to see what others are getting out of them.

Hey Mike, I have done nothing but try to get this thing running, I am going off of the previous owners word that it is a fresh rebuild .30 over with a 428 crank. I have not done any compression testing although it is strong, no burning of oil, just a couple of oil leaks. It is hard to get around this lump stuffed in a mustang.

A Ed F-427 or a Blue Thunder intake will work with you Mach 1! I wouldn't give the Weiand intake a chance when compared to the ones I just mentioned. JMHO

The old Edelbrock F427 I used to run had the tall ports for early heads.
Did they even make them to match the '69 heads?

The F-427 Edelbrock on that 390 is the way to go! It is an almost identical intake to the old 427 sidewinder intake from Ford...and we all know how good that one was. They don't make them any more but they come up regularly on ebay so keep looking. In my opinion it is one of the, if not the best all around aftermarket intake for a street FE. Good luck!