81 f100 lightweight

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May 18, 2008 | 12:02 PM

mike390

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81 f100 lightweight

I have a 1981 f100 my grandfather bought new it was my first truck and i dont plan on ever letting it go. i've had the truck 10 years now but i've never liked the drive train because of the under powered 255 v8 and its got the light weight axles regular ford truck wheels wont fit it got the small bolt pattern like a car. i just got a 84 f150 lwb body is trash plan on putting the rearend under my 81 as for the front end how much trouble would it be to swap are the spindles the same size or would i have to change the twin ibeams ?

May 18, 2008 | 01:14 PM

Franklin2

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From: Virginia

I have never done it before, but I would switch the beams and all. Go to Online Auto Parts and Auto Accessories Store at PartsAmerica.com, and look up replacement balljoints for your truck. Then look up a 84 f150 and find the balljoints for it. If they are different, then you know for sure you will have to change the whole beam.

May 18, 2008 | 03:33 PM

81-F-150-Explorer

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From: Northern California

I would change the whole beams. Especially if the 1984 has the "King-pin" system, with forged I beams. Much more "robust" than ball joints, with stamped I beams.

May 18, 2008 | 04:08 PM

woodbutcher05

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From: LaFollette Tn

I have a 1984 F150 and it has ball joints.
Leo

May 18, 2008 | 06:00 PM

wkett

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I have a 80 with the 4 1/2 bolt pattern. I think you would have to swap everything from the 5 1/2 bolt pattern truck, the disk rotors are smaller and the caliper has a different part number.

May 18, 2008 | 06:31 PM

81-F-150-Explorer

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From: Northern California

Quote:

Originally Posted by wkett

I have a 80 with the 4 1/2 bolt pattern. I think you would have to swap everything from the 5 1/2 bolt pattern truck, the disk rotors are smaller and the caliper has a different part number.

Very good point. The brakes are different.

Still a worthwhile project. when it's all said and done, the F-100 will be a F-150, with more hauling capacity, and better brakes.

May 18, 2008 | 07:02 PM

quesey

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From: oklahoma

yes it's easy to change out the i beams to get the 5 on 5.5 bolt pattern but the back you'd probably want to change leaf springs to because if i'm thinkin right the rear axel is allready a 9" most all that i've seen with the car 4.5 bolt pattern come come with the same housing just differnt axel bolt pattern with same bearings and axel size.plus its alot easier to get wheels for the 4.5 bolt pattern