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Feb 7, 2009 | 07:53 PM

#16

Redcat Diesel

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Joined: Feb 2007

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From: Pittsburgh,Pa.

I was about to reply to your other thread but I'll post it here. The F350, if you're lucky, has at best, 4.11's. Most likely 4.56's. You've got some choices depending on your budget and how much work you're willing to do. If the rear is original it's a Dana model 70. Lots of outfits around that can supply a new gear set. I would go with something in the 3.50 to 3.70 range. They would give you good road speed and pulling power without trying to rev your 390 like a ricer. Another option is to swap in a rear from a later model F350. Many of the later ones came with 3.55 gears and they can be had fairly reasonable.

Feb 7, 2009 | 08:02 PM

#17

rob1981

Thread Starter

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Joined: Feb 2009

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i like the idea of finding a different gear set, do they make a posi to but in a dually axle, where can i go to find new gear ratio like a 3.50

Feb 7, 2009 | 08:11 PM

#18

Ford_Six

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Joined: Oct 2002

Posts: 18,488

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From: The Big, Oregon

The steering box will swap over, along with the column, but the brakes won't unless you want duals with 8lugs.
The best thing would be to fix up the body on the F350 and set that aside for hauling, and get a 73-79 F100 or F150 donor for brakes and power steering on the F100.
No sense building a single "multi-purpose" rig that can't do any single thing well.

Feb 8, 2009 | 05:47 AM

#19

Redcat Diesel

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Joined: Feb 2007

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From: Pittsburgh,Pa.

Quote:

Originally Posted by rob1981

i like the idea of finding a different gear set, do they make a posi to but in a dually axle, where can i go to find new gear ratio like a 3.50

Detroit Locker makes locking center sections for most drive axles. I'm sure there are others. For a source you might start by checking with the vendors who help sponser this site.

Feb 8, 2009 | 06:40 AM

#20

NumberDummy

Ford Parts Specialist

Joined: Nov 2006

Posts: 88,826

Likes: 785

From: Simi Valley, CA

Quote:

Originally Posted by Redcat Diesel

The power steering and a/c from the F350 will bolt into your F100. The power brake booster would bolt up but I'd advise you not to use it. The booster on the F350 was designed for a truck with a much heavier load capacity that required bigger brakes. If you installed it on your F100 it would tend to lock the wheels with any more than light pedal pressure.

All 1968 F100/350's have the awful BENDIX P/S, and the corresponding F350 parts (Pitman Arm, draglink, tie rod ends, etc.) will not be compatible with an F100.

The 1967/72 F350's have 12" x 3" drum brakes front and rear, these brake parts will not bolt on to an F100.

In order to be able to use F350 brake and P/S parts, the front suspension, spindles, drums, 8 lug wheels, the whole shebang would have to be swapped, the column is different w/ or w/o P/S, the rear brakes in order for them to work would mean the Dana 70 rear end would have to be installed in the F100.

A lotta work when one considers that a 1973/79 F100 or 1975/79 F150 donor truck would be sooo much easier to get the P/S and disc brake parts from.

While not mentioned, 1968/72 F350's (and F250 2WD's) offered optional front dual piston disc brakes. These won't swap to an F100 either without a lot of work.

A Dana 70 from a 1973/85 F350: the width of the rear frame rails must be taken into consideration. The frames are wider on some of these trucks compared to 1972 and earlier, add the 3" rear brakes, the wheels will stick out past the bed.

Feb 8, 2009 | 07:02 AM

#21

Redcat Diesel

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Joined: Feb 2007

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From: Pittsburgh,Pa.

Bill, I agree there is more to the swap than the box. Believe it or not I'm also aware of the differences in the tie rods and suspension. Also I never stated anything about swapping brake parts beyond the booster. I didn't wish to insult his intelligence by pointing out differences that are very obvious.

My knowledge of these trucks doesn't come from a vast library of books and online resources but rather personal observations gleaned over 30+ years of bending wrenches for a living.

Feb 8, 2009 | 08:01 AM

#22

NumberDummy

Ford Parts Specialist

Joined: Nov 2006

Posts: 88,826

Likes: 785

From: Simi Valley, CA

Quote:

Originally Posted by Redcat Diesel

I have the parts catalogs, and over 35 years of actual Ford parts counter experience.

I've also owned over 80 FoMoCo vehicles from 1936 thru 2008, been in the car hobby since 1956.

I would never refer to any online resource, most of which I've found to be rife with errors.

While parts related items may be obvious to some, others tend to be clueless about many things.

One truck looks pretty much like another, till one delves into it.

Then there's Ford's making a running change on all the steering linkage parts on 1971/72 F100/350's.

You need the AXLE ID numbers to get the correct Pitman Arm, draglink, tie rod ends, etc...it's a fubar MESS!

Feb 8, 2009 | 08:22 AM

#23

shift1313

Elder User

Joined: Apr 2005

Posts: 726

Likes: 3

where are you located. i just pulled off the stock master, prop valve and beams with drums from a 71 f100 with power brakes. You cant have the booster but the rest of the stuff you can have for a good deal if you are close to VA and willing to pick them up.

I agree that the 350 will be your best bet. 4speed on the highway isnt bad. if 4th is 1:1 and you drop a 3.55 in the rear you will be fine. You should stay fairly low in the rpms and have better pulling power when needed.