I've got a 1985 f150 with 351w and a two barrel carb.I'm looking to upgrade to a four barrel. Will I have to change my intake? Also while I'm doing this,I will be running long tube headers and full 3" pipe out before the passenger tire.any advice or opinions please

 

Truck runs great rite now.fuel mileage doesn't matter to me.I routinely haul large amounts of hay and feed.I bought this truck because desiel was killing me.this truck pulls almost as good as my dodge.lol.debating on putting a fifth wheel in the bed and using my big trailer.

 

Yes, you will have to replace the intake.

3 inch Single exhaust would be good. For duals, I would step down to 2-1/2 inch pipe.

The cost of Diesel is offset by the mileage & ability to outwork a gas engine.

 

Yes, you should be able to use an adaptor plate. Why not just put a four barrel Edelbrock Performer Intake on at the same time?

A dual 3" exhaust is a little big for a small block. I recommend a 2.5" exhaust with Dynomax Super Turbo mufflers.

 

We'll....I don't have edelbrock kinda cash..lol.the headers,carb and mufflers were give to me off a an offroad project that never made it.I have a bender and welder.I will be doing all this,plus a 6" lift and tires all in the same weekend.the carb is an edelbrock 600...performer if I do believe? Is that to big for this motor? I was told that the motor already has a "marine" cam?don't know what that is supposed to mean.don't know the duration or any numbers? It does lope at idle. The po had cobbled the exhaust together with bits of pipe and clamps.I will be running 40 series flow masters with 2 1/2" pipe.

 

And yes,I know desiels are supposed to get better mileage and all that blah blah blah.....my Cummins get 12 unloaded and around six loaded.with fuel hovering around five bucks a gallon......it got layed to rest for a little while.

 

You can purchase a 2 brl to 4 brl adapter plate from most online part stores. It really isn' t going to gain you a power increase without a 4 brl intake. I would install an open element air cleaner and re-jet the 2 brl carb after exhaust install. Then, look for a used intake on Ebay, or save for it. Unless the mufflers are SS, the baffles will rust out internally in a couple of years. Been there, done that.

 

I've had flow master mufflers on my 78' f100 for bout 17 years.no rust??? Baffles are fine and it sounds just like it did when I put them on.I live in the middle of ga.not a lot of rust problems here.lol.as far as the carb....it was give to me with 0 miles on it.so I figured why not.the two brrl that's on there now is bout wore out.I've adjusted and tinkered and still can't get the fuel smell gone from the pipes.no smog stuff on this truck either.it also has an electric distributor? No brain box on the fender? Did it come stock like this?

 

Any Cummins getting mileage that bad is either HUGE or there's something wrong with it. And if you have big tires on it and haven't changed the speedo, that's why it seems crappy. 12V should easily be averaging over 20 MPG unloaded and 24V up to 04 should be close to 20.

 

5.9 12v....with 35's two eight inch stacks.there is so much done to this truck it ain't funny.lol.my plan was to build it as a heavy hauler.....as always, I went way over board.if I remember rite it was somewhere in the neighborhood of 490hp and over 1k torque.I may be wrong.have to look at the build sheet.I can roast the back tires at 50 when she spools up good.lol.turned out to be more of a play truck that can work rather than a work truck that can play.and yes the speedo was recalibrated with the programmer.

 

Well that explains it don't worry, I go overboard too.

 

I had a 79 400 and spent less than a grand to put intake and carb , AND radiator ,new electric fan . The bitch would lay rubber at sixty . Why would u do any work without DOING THE WORK

 

5.9L 12V, why the hell not? Lol turning those engines up is what they were made for!

 

Damn straight.lol.I have run low 13's in a 1/4 mile.... I love my truck....just went way over board on it

 

And to all the boys that"roll coal" ....my truck barely makes any smoke...lots of smoke is lots of wasted fuel and power....it will blow smoke if I lay into before it spools