The Stovebolt Site Forums The Shop Area The HiPo Shop Z'ing the frame -- Could use Advice

My 38 has Nova front suspension thanks to the last owner, which is a safe and square but ugly install in which they spliced the sub frame from the nova to the old pickup frame, so i feel no shame in further cutting away at this frame.
I do NOT want to cut the body though, which is why i am not channeling the body. why tamper with a cab thats survived 70 years without my plasma cutter just fine.

to the point:

I wish to Z the frame 6 inches front and rear. My issue is determining HOW i am going to accomplish this while keeping the frame square, but that is not what is giving me a headache.
The trouble is the frame is shaped like an A. if i cut the rails at an angle (see IMAGE of Z --TOP-- IMAGE)and stack them, overlapping the 6 inch high rails by 8 inches i'll keep the 6 inch height through the Z.
but the frame is once again, shaped like an A so the rails will be wider that will go on the bottom in the front so i have to figure out how i want to "smooth" them together while keeping their strength. I am thinking I can just stack them even offset ( Top View Picture) like they will end up being, and then box them in. I want to box the entire frame anyways before the truck is done.
( Frame Another Pic)

Now I DO work for a very capable fabricator, have access to top grade wielders who could use a little money in their pockets so the quality of the wields is not a concern, but I will be doing all the prep work, cutting and clamping everything up, etc.. but they do not work with modifying automotive frames and something of this sort is out of the norm for them so I am put in the position to source knowledge from other places and see if there is a normal or standard way to deal accomplish what i am looking to do, and to make sure this truck is safe to drive when all is done.

oh and yes i intend to shorten the truck, so stacking the rails is the known preferred method for what i am doing. I do not have a bed and plan on making a basic small flat wood bed for it to make do for a while.. eventually I will make my own bed from scratch.

I'm not sure what the question was here. If it was, "how do I keep the frame square while making the alterations", I would say to weld square tubing to the frame to hold its original shape while you z the frame.

Here is an alternate approach, similar to the stacking idea.

Rather than cut the frame and weld, first weld new rails in below the section you want lowered by Z'ing. Then cut out the old rails.

That way it should be as straight afterward as it is when you started. Or as bent as when you started...

Where in Seattle are you? I'd like to try to see this project some time.

OldSub:
I have heard similar ideas today from multipule sources. it has been decided today sense my boss seems to have a heavy interest in having the shop name on the side of my truck (the space is taken on the doors sooo... who knows) or something of the sort but were going to go with a 4link and all new frame from the back of the cab back sense i'll be building a one off bed and probably a narrowed rear end. Still open to as many suggestions as i can get. Any ideas are welcome, even the off the wall - not so thought through - ideas. who knows.. maybe one of them will fit my unusual situation.

I say unusual because the last owner took shortcuts that i have to remedy in order to set up the frame the way I need it.

At this point, I would start with a pile of rectangular tubing, a cutting tool and a welder and start from the nova sub and build new back to the rear bumper.