Hey I have posted in another group before, but I have an 81 f350 300 I6 with a single barrel carb, I’m looking at putting a new carb on an swapping to a 2 barrel carb, last I looked I was thinking a Holley 350 cfm preferably with a automatic choke, any advice or thoughts? For now I’m just thinking the carb with the adjuster plate and leaving the intake and maybe upgrading that down the road.
Thanks

 

To get the most heck anything from the larger CFM carb you need to swap intake and a header if not running EFI manifolds.
Dave ----

 

Down the road I was going to upgrade intake and other things, that trucks exhaust is completely rusted through, but I need a new carb on it to get it even running properly right now. Just not sure what carb to use.

 

Look at the Rochester 2GC.
Plentiful
simple
inexpensive
smaller bolt pattern to easily adapt to the stock 1V intake
If you acquire an aftermarket 4V intake later it will work with that also.

 

If you just need to get it running get a cheap replacement carb off Ebay.
What will a Holley or Rochester go for, then adapter (do they make one for the Roch?)
It is a bolt on, no adapters to fit any manifold, throttle will hook up with no fuss and same for the fuel line.
Many are running that carb with out issues.

Dont get me wrong as I like the Holley 2300 carb in both the 350 for a six and the 500 for a v8 as I have run both.
Dave ----

 

Ok so the thought process is don’t waste time getting a cheaper one just to hold over until a better one, I was looking at a Holley 2v with a 350 cfm and a electric choke but while reading other forums I’m seeing people say for that engine the cylinders take so long to fill with a 350 cfm to put a 600 or even 750 cfm 2v or so on it, (paraphrasing, as I didn’t even even understand it myself) I’ve not messed with carburetors too much more then just this truck in general, I have a 93 F250 with a 351W as my daily.

I’m just trying to figure out some general information and figure out what the best carb to put on that truck in the long run is.

It has a 1 barrel carb right now and the truck will run but the choke on it was taken off and so it just has to be cranked out multiple times before it will idle right.

i want to put a 2 barrel on and I’ve just been told multiple times to just go with a Holley as it is a tried and true brand but I’m just looking for something that will work with a work truck, I’m not looking for super high performance or anything but good torque and a strong motor, down the road I’ll mess with with intake and exhaust on it but it needs a new carb an a new clutch right now so that is what I’ll do before upgrading the rest.

 

You've been given some bad information. A 390 cfm carb is plenty for all but the most highly modified 300s.

A 350 cfm 2V carb is equivalent in flow to about 250 cfm of a 4V carb. That will be plenty for your needs. Even if you could get a 600 or 750 carb to adapt up to your stock intake manifold you would be sorely disappointed.

 

The 2300 Holley you mentioned, I’m on the site and I just found a 350 2 barrel reman for half the price of the new and I’m thinking about ordering that, but are you saying I won’t need an adapter plate?

The truck right now has a single barrel carb on it.
It has a problem when I crank it up it dies about 3 or so times until I sit and just hold the gas for a while to keep it running and then it will idle, the electronic choke was taken off do you think that could just be the reason?

 

What I am saying is the factory v1 carb log intake manifold is only good for the factory v1 carb.
If you put a v2 or v4 carb on that small opening intake and it will take an adapter, you would be choking off the flow of the larger carbs and in my book I dont think it worth the trouble to get the larger carbs to fit the log intake.

Now if you are going to change out the factory intake for a after market v4 intake and then use an adapter to run a v2 carb then I say go for it as you are not choking down the carb flow.
But a large carb on small intake is a no go.

As for the motor starting and then stopping a few times and you needing to hold the throttle open till it warms up sounds like the choke needs adjusting.
Have you checked the choke to see if it is closing when the motor is cold?
If it is not, try and adjusting it so it will close and go from there.
You may find once adjusted it will start and not stall and run good with out any throttle as the fast idle should keep the idle speed up.
You may not get it adjusted right on the first try so dont give up if it dose not work first time.

If you need a hand on the adjustment just ask.
Dave ----

 

The plan at the moment was a 2 barrel on stock intake with an adapter plate, is there a 2v intake you would suggest for down the road?

As said this isn’t for high performance this is for a stronger running motor with good torque as it is still for a functioning work truck.

The truck used to have an electronic choke on it and that was stolen off of it one day along with with the radiator. So I fully understand that the missing clutch is part of the idle issue.

I have to dump a bit of gas down the top of the carb when firing to get it to start properly.

 

As far as I know there is only v4 after market manifolds no v2 ones.
So to run a v2 carb on a v4 intake you will need an adapter and they do make them for this combo where the v2 cab to v1 intake not so much.
I also dont see any issues running the v2 carb on a larger v4 intake as it will not be choked off.

I kept the v1 Carter carb on the factory log intake manifold as it worked from the factory on the larger trucks like F600's
So it would work for my pulling my 20ft open deck car trailer.
I have pulled our clubs dual axle enclosed trailer not far but it got the job done even with the motor running poorly.
I have since got it running a lot better but not pulled the trailer yet.

I will say it will not win any races empty or pulling a trailer LOL

Oh you should also know they rate the CFM of the v4 & v2 carbs at different vacuum levels and why FTF said the 350 v2 Holley 2300 was like 250 CFM IIRC as that is what it would be if flowed at v4 vacuum level.
Dave ----

 

Aussie Speed makes a 2 barrel intake.
https://www.aussiespeedshop.com/prod...nifold-as0524/
Personally I would get a 4 barrel and then use an adapter with the 2 barrel carb then if you want to run a 4 you can later without the adapter.

 

$700 plus shipping that is a lot of money.
Yep go for the v4 intake run an adapter for the v2 carb and later upgrade if you want.

But no way would I run the factory log v1 intake with an adapter for a v2 carb.
Go find a straw for thick milk shakes and stick it in your mouth and try and breath.
Then start walking and then if you can run and see how far you can go.
That is what the log v1 intake with a v2 carb would be like.
Dave ----

 

Completely agree about the price, pretty wild.
I have been keeping an eye out for used Offy C in the usual places, hoping one is available and somewhat close by. Don't trust shipping and paypal etc.
mmmmmm milkshakes......

 

I’ll play around with things as the original plan was upgrade carb now and intake later as intake is fine and carbs rough, sounds like yall are saying don’t touch the carb until I have proper intake for it so that will have to be looked at as the only problem is just wait until I have enough money that I can properly do both.

The clutch has a couple issues and it needs a new clutch plate and fly wheel. Before I get into that does anybody have general information on that? It’s a 4 speed, I know there are 2 separate size clutch plates and until I open the transmission up I won’t figure out the proper I need on this truck. But as said any information about messing with this transmission?

And one more question same truck, just started to put new wheels on it today and I took off the tires on the passenger rear (it’s a dually) obviously I was turning the wrench to the left to loosen the bolts, I then went to the driver side rear tires and started to break the bolts loose as well and noticed they were a lot tighter and wasn’t able to do them as easy.

So it turns out I had to turn the nut to the right to loosen them, I only found this out after I bought a breaker bar and took it out there and sheared a bolt turning it to the left.

Why are the bolts opposite on each side? I’ve never seen this and I’m worked in tire shops, and I have a 93 250 also.
When and why was this done? Was it a common thing for that year or is my truck just wrong somehow? I have no idea about this, the drive side front tire turns left to loosen like normal too, it’s just the driver side rear wheels.

And as said I sheared the bolt off, any advice for fixing that?

Thanks for any help and sorry for the long post.