351 Windsor conversion
 

I bought an 89 F150. The previous owner swapped the motor. It has a 93 351Windsor and a C6 transmission. It was such a shade-tree swap they didn't get much of the vacuum stuff hooked up. Being a 4 yr difference I don't know what goes where. It runs rough and is only getting 11 MPG. I'm contemplating just dumping all the efi stuff and converting to.
Carb. I like simple when comes to cars. It doesn't need to pass inspection so how tough would this be? Thank you in advance for your help.

You will need a 351w Carb intake and carb, Kickdown bar for the C6, throttle cable for the carb. You will also need a fuel pressure regulator with a return, to tune down to fuel pressure to the carb to 7psi; or you will need to disable the factory fuel pump, remove the high pressure fuel pump, install a electronic 7 psi pump into the fuel line, and crimp the return fuel line.

Think about this though: Carb & EFI get the same mpg (when working properly), EFI has 20 more torque, Carb is cold natured.

Biggest benefit of carb is you can run any head/cam/intake combo.

I will post again if I think of something else.

The 351 in my truck only gets 8mpg's...I'd kill to get 11. HOWEVER, I like carbs. Easy to work on, and highly modifiable. Opt for a 4 barrel carb because you can. otherwise SC is right on the money. If I were you I would just get the pressure regulator instead of taking the rest of the pumps out and putting in another electric pump.

The downfall of course is that the EFI isn't as cold blooded, but it's not too hard of a process.

I agree with the 4bbl. I like Holley, and I like the 650 cfm with a stock motor. And a Good Edelbrock aluminum performer (operation range idle - 5500 rpm) intake.

I have a EFI 351w:
I get 14-16 mpg, depending on how I drive. I am running on a fresh rebuild, completely stock; with no cat, smog, or EGR.

If I understand correctly the 351 is a 302 block? Will any manifold off a 302 fit? I'm gonna need to get most parts from the junkyard. Which motors can I ask for parts from?

NO, the 351w is NOT the 302 block. The 351w and 302 have the same bore size, but the 351w block is 1/2 taller, because the 351w has a 1/2 longer stroke. So the 351w has its own block.

Now, the 302 and 351w does use alot of the same stuff. I think the manifold can work, I am not real sure. But they do use the same piston, water pump, belt system, timing cover, valve covers, and motor mounts.

To be on the safe side I would try and get exhaust manifolds off of a 351w. The 351w intake manifold is larger than the 302.

351w is wider than a 302... so the 302 intake will not work..

ok, on to the next step
 

Thanks guys, now I start rounding up parts. What year model 351w's will or will not have a compatable intake manifold when shopping boneyards? Thank you again

Any 351w intake manifold from 1977 (ish)-1987 will work. 351w intakes from 69-76 had more bolt holes.

Defiantly check out 80-86 & 87 body style F-series and bronco. Most 351w came with the 4 bbl intake. (however some had the 2 bbl intake) If you find that body style bronco or F-series (again 1980-1986, then 1987) with the 4 bbl 351w HO then you can take the intake, carb, distributor, electronic ignition box and wiring, and throttle cable.

The 351w became EFI in 1988.