*I started a thread over in the 300 I6 forum. I thought that would be a better place for this*

Hi all. I lurk here quite a bit to soak up some knowledge, but couldn't find the answer to what I'm looking for. I have an 86 F150 300 I6 that I'm looking to replace the stock intake manifold and carb with the Offy 6019DP 4 bbl and a Holly 390. I'll upgrade to some efi exhaust manifolds, but im saving that for a later date when I have more time on my hands.

I'll be taking off the EGR "spacer" and not replacing it with anything; it'll be carb on intake. Will I need a spacer to make up for that? Does the offy 6019DP sit higher than the stock intake? Will a roughly 1 inch spacer in between be too tall and I'll have to adjust elsewhere to make this setup fit?

 

A lot of people put a spacer with the heater hose water going through it. If you are going to drive this truck in cool or cold weather, the carb hanging out on the aluminum intake with no heat to it will be very cold natured and take a long time to warm up. That is why the factory sat the factory intake on top of the factory exhaust manifold.

 

Before you get that intake read this thread and really look at page #2 on the cable hook up https://www.ford-trucks.com/forums/1...nline-6-a.html

As was said in the 240 / 300 motor area the new intake does not use a EGR, the carb bolt right to the manifold.
If you do go with the DP manifold and use an open spacer it kills the reason for the DP manifold use and you should just go with the open one.
I think like they say just go with the open type and you will be good.

As for the EFI manifolds later do them at the same time as the intake for 3 reasons.
You would need to take everything apart again as they use the same gaskets.
You are putting more air into the motor but you are not getting rid of it so you dont gain anything with just the intake manifold.
And the big one the factory exhaust manifold has an opening at the top where the intake & exhaust manifolds bolt together to put ho gasses to the bottom of the intake.
I dont know if the log exhaust will bolt to the Offy intake and no one has done it because the log does not flow good.

In short do both the Offy and EFI exhaust manifolds at the same time.
Dave ----

 

Thanks Daves.

I actually was looking at the coolant passthrough spacer before I posted this. Good to know other folks have done it.

Unfortunately, I will only have 3 full days to do this, which is why I was waiting to do the EFI exhaust later (And exhaust fabrication). But since it sounds like it's going to end up even more hassle or not even work at all with the log manifold, I might have to wait. I have a decent vacuum leak at the base of my carb; the stock intake manifold looks like a toddler took a rasp to it. No matter how much I use emery paper or rtv, the leaks just don't want to seal.

 

Can you stack gaskets and RTV to stop that vacuum leak?
You know the factory has the manifold / gasket / EGR plate / gasket / carb.
Can the manifold to EGR gasket be the leaker? I know that gasket should be a high temp type gasket where the carb gasket is a normal type gasket.

Now you can do as you wanted and it should fix the vacuum leak and now that I think of it the exhaust manifold should bolt to the intake as the gasket is the same and what I used for a pattern to make a gasket for the water plate.
It will also work just not to it's fullest as you are choking the exhaust outlet.
Me I cant see why the vacuum leak cant be fixed and save up for the EFI manifold swap when you do the intake but that is me, lazy and not liking to do a job twice.
Good luck on what you d.
Dave ----

 

I haven't tried doubling up on the gaskets to be honest. I'll give that a go today. I've got the efi manifold and some walker y pipes already on the way, so maybe I can try to mock up the exhaust and what not before hand so the install goes quicker and I can get it done at the same time. I was trying to be conservative with what I do during those 3 days, because things that are 5 hour jobs usually turn into 2 day jobs for my truck haha. Plus, this is my daily driver with no backup vehicle, so everything becomes riskier.

Reading through that link you posted, the throttle setup is going to be an issue. You mentioned a bell crank bracket possibly working. How do you set that up? I can fabricate brackets to mount it later this week, I just have to wait until the intake and carb get in later this week to see where I'm tight on space. I have a 36 in accelerator cable already. I was looking at getting a 40 in one to be safe, but don't really know how that carb sits on the intake.

 

I think I would get all the parts together, EFI & intake manifolds to check if the thick washer mounts are even, they have to be when placed on a flat surface.
Then I would place the carb on the intake and see what measurements I can get from say the face of the Offy manifold to the throttle hook up on the carb and then get a measurement of the factory manifold face out to the measurement you got from the Offy / carb and see where that puts you. The from that to the HVAC box to see if you will run into the same problem of the cable hitting it.

If it will hit the HVAC box and I think if you have factory AC it will, you will need to come up with a bell crank set up.
Everything I found was a 90* type and I cant see that working right.
Flat stock with 3 holes, 1 at either end one for the throttle cable the other to the carb.
The center hole is where the pivot is and will rotate the flat stock. if you push / pull 1 end the other will pull / push.
You would need to make a bracket for the pivot that the flat stock would pivot on.

Now how long either side of the flat stock holes are from the pivot is up to how much throttle the carb needs and the pedal moves.
If you change 1 side f the holes the ratio of how much the other end moves will be changed.
This is something you will need to play with and figure out and you might be able to do it before the swap.
You can measure how much the cable moves now then measure the carb throttle movement and go from there.
Maybe when you make the flat stock put a few holes at either end so you can move the cable and carb hook ups to see what works best for you.
I just dont know how this bell crank could be mounted as I dont have an Offy intake to look at.

Maybe others can show what they hooked up the throttle cable even being a different way the carb is mounted and see if you can use something like that?
They are all just thoughts as I dont have this set up
Dave ----

 

Keep RTV away from gasoline. The gasoline turns the rtv into a slimy goo. You can try the black permatex or seal-all. But the seal-all will be pretty much impossible to remove.

Be careful with thick or doubling up gaskets. You can do it, but carefully tighten the carb down, but not too tight. The stacked gaskets get squishy, which is what you are looking for, but it gets very easy to break the mounting ears off the carb if you tighten it too tight.

Factory thick insulator gaskets usually have a hard plastic bushing where the mounting bolts go through, to keep from overtightening the mounting bolts and breaking the carb base.

 

Gotcha. I did some rough drafts around how I'm looking to set it up.

Draft 1:

Draft 2:



Bell crank setup draft:


Let me know what ya'll think.

 

It looks like you got what I was putting down
What if you put it between the valve cover and carburetor and stood it up on end?
It looks like you have it laid down flat. Or maybe have it over the valve cover like you have it.
But it is your truck and you are there looking at it so you know what will work or not so go with what you think will work best.
Dave ----

 

Honestly, those are good ideas too. I'm going to pre fab the bell crank before hand and see where this would fit the best once I get the setup.

 

When doing after market custom installs it is all about the pre fit before the install this way any "got you" should be small and not a job stopper.
Dave ----

 

I have never worked on a six, so educate me. Why does the carb have to be mounted like that with a bell-crank? What keeps you from turning it around and mounting the throttle toward the radiator side? I am sure there is a reason but I do not know what it is. That is a square bore carb, so the bolts should line up either way?

P.S. I guess the throttle linkage hits something if you turned it 90 degrees instead on 180 degrees? Or possibly the bolt holes don't line up at 90 degrees?

 

When using the Offy DP (dual port) intake manifold the carb can only be mounted 1 way and because of this and the way the throttle works the cable has to co in from the HVAC box side.
Now this ay not be a problem with a non-factory AC box but with the large AC box the cable hit it and makes too sharp of a turn and does not work right.
Did I put a link to a member that asked how to fix this problem in 1 of my posts above?

If you use the Offy C manifold you can mount the carb any way you want but you have to note were the primaries / secondaries of the carb are and the way the cylinders are for lean / rich running.
Dave ----

 

Just a quick update on how it's going. Ill be putting it all in over the next weekend.






Nothing is permanently attached and I was just mocking everything up without gaskets. My next issue to solve is the springiness of the bell crank. I used 1/8 in steel to go under the fuel bowl and bolt onto the carb studs, instead of 1/4 in. After that, I have to find a solution for where the throttle will connect to near the engine to allow for pull.