shortening my frame

[fords_forlife]

i know this question doesn't pertain to 67-72 trucks but i thought i might ask it anyway. i'm currently working on a 1980 f-250 ranger lwb and have always liked the way the old style stepside box looks with the square fenders. so anyway, i was wondering if anybody might have some tips they can give me on shortening the frame to fit the stepside box, where is the best place to cut the frame, will any of the original mounts for the box line up with the stepside's, will the side mount gas tank filler neck work for the stepside, i'm re-running the gas and brake lines so i don't care about those, if i cut out the difference in wheel base length can i use a swb driveshaft or should i put the swb driveshaft in the tranny and measure the length to the yoke on the rearend. am i missing anything, any help would be greatly appreciated.

[FORDification]

I agree that you'd probably have a lot less money and time involved with just finding a derelict truck to use as a parts vehicle. Your fabrication time would be cut to almost nothing, it would simply be a matter of swapping parts.

[willowbilly3]

Since you are working with an F-250 you may find that a shortbed frame frome an F-100-150 is considerable different. Also the 1/2 ton pickups in 1980 had the swiss cheese frame with oll those big holes in it. I say if you know how to weld and have a way to keep it all straight while you do it then go for it. Measure everything several times. The bed mounts will probably not come close. Use a bed from 73 and newer so the frame widths are compatable to save some fabrication. Where you make the joint in the frame you will want to fish plate it inside. You can do it on the outside but that looks ugly and if you grind the welds good it will be un noticable. When you cut the fish plates try to make them about a foot long if you can. This step isn't critical but is a nice touch for added strenth and looks , taper the ends of your plate about an inch on rach corner and take the taper back about 3 inches. Now here is a very important detail, DO NOT weld across the ends of the plate. You should weld the taper part but never weld across the end of a frame plate as this will cause a weak point in your frame.