390 engine build up

Reply Subscribe

Thread Tools

Search this Thread

Dec 13, 2005 | 09:31 PM

slinger34

Thread Starter

Senior User

Joined: Dec 2005

Posts: 350

Likes: 0

390 engine build up

Hey iam new to the forum. first post. So i got a 390 Fe engine for 300 bucks and i am putting it my 79 F-150 which should bolt right up the 4-speed. anyway i was thinking of putting some mods in it. my idea was this . edelbrock rpm intake, Isky 270 megacam, flat top pistons. and four barrel carb, and headers. Iam thinking this combo would be good for at least 400 hp or close to. It seems that i could do this pretty cheap. I have a feeling that i would need to get new valve springs to handle the higher lift. would this cam even work for the stock heads. any suggestions are good. so thanks to anyone who reads. Thanks

Dec 13, 2005 | 09:45 PM

Boltgunner

Senior User

Joined: Sep 2001

Posts: 350

Likes: 1

From: Friendswood TX

I too have a 390 and would like some info on what would I have to do to get 1 HP per cubic inch or thereabouts. Can it be done without internal part changes? That is, going with a head/intake/header/carb/ignition upgrade, would that do it? If not, spell it out, please!

Dec 13, 2005 | 10:31 PM

Mil1ion

New User

Joined: Jan 2008

Posts: 0

Likes: 24

Welcome to the site !

Just a head's up !

FTE has specific engine forums for engine related questions.
Plus, there is the performance forum as well.

Dec 13, 2005 | 11:29 PM

rusty70f100

Post Fiend

Joined: Jan 2003

Posts: 8,600

Likes: 4

From: Iowa

First, stock unported heads are not going to get you to 400hp, no matter what cam you put in. Fortunately, FE heads respond extremely well to porting.

That Isky cam surprisingly works ok in Desktop Dyno, but there is a better one, see below.

Here is my formula for getting 400+hp out of a 390, in no particular order:
1. Port the heads. If you know how, then do it, otherwise learn or have 'em professionally ported. Head flow largely determines horsepower, so do a good job or tell someone to do a good job.
2. TRW L2291 forged pistons
3. Crane 343941 cam, matching springs
4. Adjustable valvetrain (ask for specifics)
5. Good flowing dual plane, like the Edelbrock Performer RPM.
6. Around 700cfm carburetor, or fuel injection if you're feeling adventurous.
7. Headers and dual exhaust
8. .020" thick steel shim head gaskets. Mr. Gasket makes 'em.
9. A roller timing chain will help.

Hey, I've just described my motor!

Of course, there's a whole lot more to it, including basic engine building, balancing, and a whole load of clearances, torque specs and theory that you will learn if you dont know it already. I suggest you buy books and ask questions if you're not absolutely sure what you're doing.

Dec 14, 2005 | 09:36 AM

slinger34

Thread Starter

Senior User

Joined: Dec 2005

Posts: 350

Likes: 0

Thanks for the Ideas. This gives me alot more to think about, and since I wont get out of college till May I have time to scrounge up extra cash. Thanks again for the info

Dec 14, 2005 | 01:44 PM

charles jones

Elder User

Joined: Mar 2005

Posts: 709

Likes: 0

From: Mesquite, Texas

I think it would be wise to check your bell housing because I think if stock it fits a 335 or 385 series as I believe the fe stopped in 76 in f series trucks. What engine is in it now?

Dec 14, 2005 | 03:00 PM

slinger34

Thread Starter

Senior User

Joined: Dec 2005

Posts: 350

Likes: 0

I pulled the 390 out of a 1970 F250with the bell housing and tranny still connected. So It should mate to the 4-speed that is in my 79. The only problem i will have is that the motor mounts will need to be custom built. otherwise I am sure it will work. Right now I have a 300 that is just about to blow. When it warms up i cant keep oil pressure. So I wanted a V-8 and it was a good deal.