I'm going to start looking for a cast iron factory 4bbl intake for my truck. I've thought about the Eddy Performer and a few others but for my use I don't think it's worth the money. The truck is a 1970 F250 2wd Crew Cab. It has a stock 390 with headers and a C6. I have a Autolite 4100 1.12 venturi 4bbl carb I will use. This truck is a daily driver & my camper tow vehicle. I don't exceed 60 mph and don't turn the engine past 3500 rpm on the hills. I'm looking to make the most power from idle 3000.

Is there a factory 4bbl intake I need to stay away from for my use?

 

If you don't run over 3500 rpm, why even bother with a 4bbl?

Iron manifolds with an "S" or a "T" would work.

 

The weight difference is enough to justify the expense IMHO. A real back saver.....

 

I just like the Autolite 4100 on a daily driver. Right now I have a Holley 2bbl 4412 500cfm. It works well but I just want a 4bbl. I'm gathering parts for a future change. I have acquired a few Autolite carbs and am keeping an eye out for a 4bbl intake. I have a few guys near me that have FE parts and wanted to know what to look for the next time I visit them. Most discussion of FE parts on the net is about wide open performance and that's not what I need. I wanted to see what other guys with trucks have ran and liked.

 

from what you said I don't think you are going to see any benefit doing the swamp to 4barrel . the cast intake weights is like 70lbs

 

Mike,

I guess that's why Ford put the 2bbl on the trucks to begin with. Thanks for your input. All the car guys are go 4bbl but I wondered what the trucks guys experience have been.

 

If it ain't broke, don't "fix" it. But, If you're going to hunt for an intake, hunt for a used Edelbrock Performer to replace the 2 bbl with. At least you'll get the weight reduction. Replacing the iron 2 bbl intake with an iron 4 bbl intake is a HUGE waste of time and energy.

 

I had better fuel economy with a 4V; 12 MPG. If the price difference is significant, I would not worry about shaving 50 lbs off a 3/4-ton truck. The last iron 4V intake I picked up cost me the drive across town, and I had to pick it up by myself.

That said, you want to avoid the older intakes with the tall runners. If it has an S or T cast in the runner, it should match your heads. Another consideration is the funky EGR port Ford cast in the newer manifolds. That is not what I would call one of their better ideas.

My "free" intake. I found the spacer on one of my junkyard runs.

 

The 1966 (S)iron intake has the large 2.5" thermostat which did not seal very good with an old thermostat housing. Plus those big Thermostats are special order ,where as the 67 up all the thermostats were 54mm which just about every auto parts store carries.. Just some think about when buying an intake..

Plus I've run a 2 barrel autolite carb for a few yrs on my 390 camper with stock cam, only 0.30 bore..

Add 4 barrel iron heavy intake with 4100 autolite and mileage was about the same most of the time other then driving in hilly areas. But did ad little more get up & go and was happy with the added power mileage 10-12 .

Then got a little crazy and added a low end rv cam then added Edelbrock intake and a 4160 600cfm Holley and down went my gas mileage to about 9-10.

Since then changed cams did some exh. & intake port clean up added 428 crank drown from 9'7 compression down to 8.3 so, I can run regular 87 octane gas when needed as when the price gets high. 5spd o/d tranny
It still runs better and faster now with the lower comp of 8.3 as the the 428 crank made up for the loss of the higher compression..

Still running about 10-13 mpg with no camper that is, when drive like my age group..


Orich

 

I wondered when the thermostat changed. I will not buy the old style. I'll take a thermostat with me when I go hunting.

 

On a motor that sees a lot of work the cast intake is a better choice .. It will deal with heat much better than any aluminum intake .. Plus the factory 4 barrel intake will be dual plane and that would be the choice for a work horse .. I would also add that the headers you have will be unleashed once you have a 4-barrel .. I stopped pulling cast iron intakes long ago by hand .. My engine hoist does the job just fine ..

A couple other things I would add to your work horse are a high output coil and bigger spark plug wires to get more complete combustion in the hole and to reduce sludge build up in the motor add a catch can coming off the PCV so the heavies drop out before being reintroduced to the motor .. This cuts down on the sludge significantly over time and in turn allows the motor to run more efficiently ..

 

Look at the cast ID number by the big (S) C7AE was the first yr. that came out with the smaller 54mm size thermostat..

Large thermostats came in all the earlier yr vehicle and c6ae should have been the last yr. May be their could have been a mid yr change for this.
I don't know..

Orich

 

Catch can, that's a good idea. Do you have an idea or picture of how to do this?

 

This is how it works



This is a pretty good product there are many more choices these days search "PCV catch can" Catch Cans



Another type



and another

 

With todays high detergents oils are much better cutting down on sludge build up.

Also using a high enough of a thermostat helps reduce the built up of sludge

I've seen only one motor with a catch can and it was a Chevy small block.

That motor had well over 200 thousand miles on it. It had a lot of blow by like crazy. The valve guilds were also warn badly and the stem seals were hard and cracked and not doing their job adding to the need for a catch can.

My 2cents on the on a catch can.
orich