I'm trying to decide on an intake / carb setup for my 4.9 I6. I'm rebuilding a salvaged engine. Nothing fancy but I'm looking for good performance across the rpm range and good low end torque. Basically, a solid and dependable runner.

It's going in my '85 F150 4x4

I'm thinking an offenhauser C intake but the carb choices are overwhelming:

Weber 32/36 DGV?
Holley 390?
Holley 600?

Any of those work 'as is' or will they need to be re-jetted? The block is an EFI one so no mechanical fuel pump. I can machine it for one, but I hear in some cases an electric pump (Carter 4070) works best.

Bottom line; I'm looking for some advice from someone who has actually done any of this.

Anyone?

 

My vote is an Offy C series and a motorcraft 2150 off a 302. I had a holley 390 and never could get it just right. Bolted on the 2150 and never looked back.

 

What size 2150? 1.02? 1.08? 1.14? 1.21? ,etc.

KsCop: you might want to open the hole for a stock fuel pump. This would give you a choice of a mechanical or electric fuel pump. Plug the hole if you don't use it. Just a thought.
thanks, jack

 

Have you actually done that? If so, how was the carb jetted? Mechanical or Electric Fuel pump? What fuel pressure?

I'd like to go with a new carburetor vs salvage or rebuilt. Haven't had much luck in those areas..

 

If you use a 4v carb on a C manifold, install a spacer with 4 holes between the two. The Edelbrock 1403, 500 cfm, is an out of the box carb. Mine was install and run. They also make a $50 tuning kit with jets and metering rods, etc. The box offers an easy chart, and it is simple to swap jets and metering rods.

And yes, used carbs are a crap shoot. You never know if the po has drilled orifices or not, making the tuning of said carb impossible.

With either the C or DP intake you'll need a heating plate on the bottom to maintain good driving manners and stabilize the intake temperature so the fuel/air mix doesn't puddle inside the runners.

Good luck.

 

"Any of those work 'as is'..." Best to figure that nothing works 'as is' and will require some tuning. The jets will be one of the last items in the tuning process, not the first. One has no way of knowing about the jets until the engine has been run for a while.

 

Yes, I actually did it. I used a 1.08 2150 with the metering rods in it. I dont remember for sure, but I think I upsized my jets. I drove it and if it surged at cruise, I just kept upsizing until that went away. This was on my old truck, so I am going off memory

 

I realize any one of the Autolite/Motorcraft carbs will start and run on a mostly stock 300 six. Since Ford made many sizes of these carbs (for different size engines) from 190CFM to 424CFM, i was interested in feedback from actual use of these different sizes. Both carb size and jet tips.

Thanks to all, ...jack

 

hey Ted
im doing this right now I have a 356 cfm off of a 69 cougar 351w
do you remember what throttle cable bracket set up you used ?

ty

 

I hand made one. I bent a piece of metal that held the cable at one end, the spring at the other and was bolted down by the carb studs

 

Ok ty
im modding the orginal 2bbl bracket.
same setup.

 

Clifford & Holley 390

 

 

Looks nice!

 

I picked up a Clifford intake with a Holley 4548. I'll see how that works out.
I just dropped off the block, head and crank at the machine shop today. On first inspection, it all looks in good shape and will require minimal machining.

Also orders a new cam, timing set, lifters, springs and push rods. Went with a Comp Cams 260h.

Machinist said he'd be done next week and then I can see what I need to order.

One step closer..