I want to build a 400 for my f250 4x4. I've read numerous discussions on this topic and just need more feedback. I want an engine for normal driving,occassional towing,and jst all around great performance.
CR ratio
carb cfm and what brand
cam both hydraulic and roller
intake
headers and what brand
Anything else would be appreciated. Also auto tranny.

 

If you went around in here you would find hundreds upon thousands of build ups with all the different recipes that you could imagine. Just search for a similar topic.

 

Thanks. I'm from Helena.

 

CR = 9:1
Carb = 600 CFM Edelbrock.
Cam = Comp Cams 265 DEH or better 270HR.
Intake = Weiand 8010, or Edelbrock 2171, or 3771.
Headers = What ever fits?

What else = Double roller chain, Roller rockers, some porting on the heads, stainless steel valves.

Tranny = C6 with shift kit.

 

What kind of horsepower and torque can I expect and why the shift kit. Thanks.

 

With a 400 +0.030 and some head work using a 265DEH cam.
Torque = 433@2000, 438@2500, 438@3000, 434@3500, 421@4000 RPM
HP = 338@4500 RPM
With the same motor with a 270HR cam:
Torque = 466@2000, 470@2500, 473@3000, 476@3500, 466@4000 RPM
HP = 375@5000 RPM.

The shift kit gives hard crisp shifts. It isn't necessary, maybe you would prefer an overdrive unit.

 

Try the HOt ROd article on the 400 They got something like 420HP and 435TQ byjust cleaning up the heads mild stuff like that all for $2,000 I plan on following the article on my 400.

 

where can i find this hot rod article? that sounds like what i may just need

 

Danlee, what kind of gas mileage should I expect with this set up. Thanks.

 

I don't have the link for the article here, but if I get to work tomorrow and find that no one has updated this thread, I will put it in here.

I have a 351m in my '78 and want to do the same as you. I am thinking along these lines...

Stock heads with porting and 3-angle valve job.
Comp 265DEH cam K-Kit (comes with valve springs, timing chain, and some other goodies)
Weiand 8010 Intake
Holley 600cfm carb
Hedman Headers

In all, from what I have read, this should make the motor twist around 350HP and 400@4500 torque. That is a rough estimate.

My 351m is in good shape right now, but when I go to get another short block, I will likely get a 400 because it has the longer stroke. Other than this, our motors are the same.

I agree about the shift kit in the tranny. But I would really like to have an OD for the highway and traveling. I have not decided what to do about this yet.

 

Does anyone know what kind of gas mileage I should expect. It can't be much worse than the stock condition it is in right now. Also I know that at one time it was a full time 4x4 and someone changed the hubs or did whatever to it. What is it now and should I be concerned with this. Basically the truck was taken care of pretty well and the guy I bought it from changed it over and had a shop do it so I really have no history of what exactly was done. Thanks.

 

I get about 12 mpg in my bone stock 79. Im gonna venture to say that you might get a little less if you baby it with all those wonderful modifications, but if you punch it, well we wont go there on the gas mileage...hehehehe

 

The Hot Rod article got 468 ft-lbs torque and 380 HP. The piston that they used is no longer available. The cam that they used would put that motor on the edge of detonation with 93 Octane with 9.45:1 Static Compression. The cam is OK, but they should have no more than 9.0:1 CR. The heads were heavily ported.

 

This site is great I wish I would have found it earlier. You have given me more info than I have found spending countless hours searching on the internet. Thanks.

 

Here is the link for that article....

http://www.geocities.com/styleline58/400.html