Lengthening a frame? Advice?
 

I am thinking about lengthening a frame to fit a crewcab and longbox. I have seen other guys lengthen frames, but I have also heard a bunch of "oh no, don't do that."s. Any advice?
Thanks

Did you get a chance to read my reply in the 73-79 forum? I gave some ideas there. Let me know if you saw the post.

Yes, thanks. I am trying to keep my posts as relative to the forum as possible. I don't know if our state inspections will allow frame fab. for on-the-road use, but I'll try to get a "farm truck" plate ... whatever I do.

i could be totally wrong but, i would think that lengthening the frame would make it weak at the weld spots. i would think that just buying a longer frame would be safer, but probably more expensive

Its actually not that bad if properly done, and that would mean staggering the cuts (step them, and be sure that they cuts are not parralell to the opposite frame rail), reinforcing the joint as well. But if you are just a stage or 2 above a hack welder hire a professional, but do the prep work before hand to save even more money.

I see this happening alot in trailers and big trucks (bigger than what you use as a DD) and i have yet to hear of any major problems related to a stretched frame.

mustange is correct with the addition I would plate it also in a diamond shape over the welds atleast on the outside of the frame this wil add alot to the strength, of both the total frame, and the welds themselves

Also wouldn't hurt to box the frame in over that are and about an additional foot either way as well.

What does boxing the frame mean? I just know they make a big deal about the 04's having boxed frames from the factory.

it means that it looks like [] instead of just [

that is if you were looking at it lengthwise.

may be off the topic but i need help. ive got a 74 with a boxed frame and i need to take the cab off which means i need to cut into the inside part of the frame to get to the body mounts and i dont have a cutting torch. how else can i do this? please help me.

Electric of air powered die grinder is your next best tool for something like this, probably the 4.5" angle grinder would be good enough, but if you have room use a 7" angle grinder if you have access to one.

I was told to just use a sawzall but that would mean i have to cut into the actual frame a tiny bit. will that effect anything?

Shouldn't matter to much, and with the frame already being boxed i wouldn't worry about it to much.

yeah i guess. thanks for the help, if i have any more questions i know where to come. thanks again.