I'm planing on using a 75 frame under my 66 8' /styleside F 100 and I read here sometime ago that I would need to move the rear axel forward 3 " to be in the center of the wheel well opening of the 66. Is this correct? Dosen't seem like to big of a deal. Besides that and the shock mounts is there anything else that needs to be done. Thanks, Tom

 

FordboyPete, says you can do it without, by setting the cab & clip as far back as you can get it and adding a little more space between the cab and bed.

The worst would be moving the rear axle forward. The cab & clip mount points are the same.

If you haven't separated the cab & clip yet, try lifting it as one piece and moving the chassis below. You won't have to spend all the time lining everything back up.


John

 

John, that only works on a SWB version. LWB (8"-0" Bed) is full 3 inches longer and that's tough to fudge or hide.
Also Tom frames from 73 up are +3" wider in the CA or Cab to Axle area, but all that takes is remounting the bed by making new holes +3" wider than 65-72 frame. but it's not really a big deal. In passing 66 Bumpers do not bolt up right to a 75 frame but the 73-79 bumpers fit very well and only a real picky purist will be able to see them, Most people have no clue what so ever whether it's a 66 or 76 bumper.

FBp

 

So what your saying Fordboypete is I need to go ahead and move the axle 3" ahead also I am puting the 75 bed floor in the 66 bed so the mounting holes will line up I hope. I also need to repair the frame where the cab mounts go and I don't know what size hole it should be. I'm guessing about 1"?

http://s40.photobucket.com/albums/e2...t=HPIM1988.jpg

http://s40.photobucket.com/albums/e2...t=HPIM1987.jpg

 

Tom,
My short answer is Yes,

IF you plan on using a complete '66, 8'-0", bed assy, on a 73-79 frame you will probably have to move your axle forward -3" to shorten the wheel base enough to get your wheels centered in the wheel opening precisely.

Having said that, you're better off slicing 3" out of frame section rather than trying to move the axle forward by sliding your perches & shackles forward in the existing arch. The arch is minimal to begin with. Moving your axle center forward within it, may result in axle housing, or springs contacting the frame bottom on bumps, or with weight, or hard traction applied. It definitely will create problems with rear shock mounts. It may also affect your rear anti-sway bar mount, or make adding a rear anti-swaybar difficult or impossible later if you don't have one now.

Also you mention using '75 bed floor w/ your 66 bed sides. Location of wheel wells in the 75 floor is 3" different than wheel openings of your 66 bed sides plus the floor is +3" longer than a 66 bed is. . . . HOWEVER ---->

If I was doing a Long wheel base frame swap, I'd choose the last option. I'd center my '66 wheel openings to wheel housings of 76 bed floor, then add sheetmetal to '66 bedsides, where it's lacking, to make them as long as & to fit the layout/ positioning of '75 bedfloor. I would NOT CUT, or move anything on my frame. Others will disagree with my methods, but I won't break frames.

I can easier do sheetmetal work than frame work. Altho I fancy myself to be a fair welder, own a shop & equipment to do either, bedsides are cosmetic but the frame is what puts my 460 power to the pavement. I wouldn't wan't any chancey propositions there. I know about plating and diamond patterns and all that, but I want my frame/ chassis to be one piece from my engine & trans mounts to my rear shackles free of splices, rewelds or any potential problems.

This is just My Humble Opinion Tom.

FBp

 

Look, I've been a member here for years. I've offered my opinions & my solutions and/or advice many times to many people on many topics. I could just que up FTE and it would open to the forum I chose. But lately I have had to log on to every forum I wanted to visit. I don't need that and I don't have the time to waste just to feed a data base I know nothing about. . . . . Sorry.

Suddenly what has changed ? For one thing my security informs me "This website is now harvesting information by using a scripted window. If I trust this website, (I should) click the approprite icon.

Well Guess what, I don't trust any website, but especially those that want to harvest information on me in some semi secret manner with my permission but not my knowledge of just what information is being harvested. Sorry I don't play those games.

I suppose I will not be visiting here or posting here any longer. My security system is telling me to beware so I will respect that. I am forced to join several others who were once "regulars" here at FTE for years also, but do not participate any longer either, for similar stupid invasive, reasons.

On That sad not I bid you all farewell, I have better things to do than "log in" everytime on every forum, and grant my permission to secretly give away my own personal information automatically, the content of which I have no clue of. . . . . Call me Old fashioned, call me **** but if you want to be really accurate call me. . . . . GONE. . . . . . I am Outta Here Folks !


Just one more disgusted former member of this once great website & forums.

FORDBOYpete

 

Sorry to see Pete go, loads of info but he stated :

Also you mention using '75 bed floor w/ your 66 bed sides. Location of wheel wells in the 75 floor is 3" different than wheel openings of your 66 bed sides plus the floor is +3" longer than a 66 bed is. . . . HOWEVER ----> :

I measured the bed floors today and found them to be of the same size in length and width. It looks to me it would fit perfectly . Tom

 

Tom, You are correct. I have a picture saved on my hd of a mid 70s bed floor with Slick sides. I didn't get real close with the measuring but I have a 86 that measures about the same. The bed size is much closer in size even though the skins are different. I remember going to the local Ford dealer a while back while the trucks still had I-beams and noticed how similar the mount system was to my 66.

The issue is the bolt holes in the floor are in different locations. You will need to either drill new holes in the bed, or weld plates under the bed to fit the different holes.

John

 

jowilker, I am going to use the 75 frame and the 75 bed floor with all the channels attached . I removed the bed floor by cutting the spot welds around the perimiter of the bed floor and left all the rest of the stuff there so it should bolt right up to the original holes in the frame and original holes in the bed floor. I am going to move the axel instead of cutting the frame. Seems like the easier thing to do. Thanks, Tom

 

Good luck, and don't forget to follow up and let us know how it went.

John