Back half w/ 4 link

[Windsor]

Well folks, I'm going to have a few weeks (or more) to figure stuff out for my frame build under my '40. I already have the front half of a 89 Dakota frame (plus cab floor and firewall which I will graft into my car). I am looking into the Chassis Engineering back half kits through Summit along with a couple other manufacturers of the kits. I know I want to go with a 4 link for better streetability over ladder bars, just need to find what will work best for me since I am not looking to drag the frame or brackets over speed bumps.
My plan is to extend the Dakota frame to the length I need to mount the back half using either 2x4 steel tubing or bigger if I can find something closer to the size inside the rails. The Dakota rails are like C channel with downturns at the edges. I am going to step cut the original rails and I am still trying to figure out the best distance to insert the extensions into the rails. I am thinking all the way up to the point that the original rails are boxed.
If the back half is made of 2x3, and I am using 2x4 or taller tubing, I am going to notch the end so the 2x3 sits into the 2x4 at the bottom. This will give me a little more rail to ground clearance, and if I leave the top 1" open, it should assist in airflow to help the inside dry out a bit. I am not opposed to boxing the end if someone can give me a better idea on airflow through the rail.
I know I will ditch the diagonal pan hard bar and go with a parallel panhard bar mounted on the top of the housing and level at ride height. I'll also be using the same material as the frame as bracing from the rails to the rails on the back half. I will probably end up getting told I over engineer it, but I'd rather it be overly strong insted of snapping in half going down the road.
If anyone has any pointers or ideas, I'll be happy to hear them.
I am looking into the Tin Man Fabrication motor mounts for mounting the big block and I will have to build a new trans crossmember. And I have to get a new driveshaft made since I plan to move the rear end back about an inch to clear my rear fenders if I decide to use 33" tires, it will also help the look of the wheels in the arch.
I am looking at going with a 3.55 ratio with my 27" tall tires.

Thoughts?

[Windsor]

Alright. So, I've decided that I'm going with 2x4x3/16 rectangle steel tubing. And a CA Chassisworks 2x4 back half with 4 link.
I am going to cut my frame more to remove the tapered C channel and reshape the OE boxed section where it tapers. What I lose in strength from the taper, I will re-gain by using angular bracing. Removing the taper will also allow for more adjustment in the floor replacement since it will sit about 4 inches back from the OE location.
Each frame extension will be a total of 6' long with just shy of 2' inside the OE boxed frame section.

[Windsor]

[RCCDrew]

Very cool. Subscribed!

[Windsor]

Cut the C channel off. Step cut the outside segment of the OE rail. I will cut the inside segment to fit the crossmember once I build it. It will be 2x4x3/16 like the new rails, but will have a driveshaft loop and two 4" exhaust pass throughs.

Still kinda hard to get stuff done. Docs orders are no gripping, no pulling, no lifting more that a can of soda for another 4 weeks. So I'm having to do all my work with my non-dominant hand which has a sliced open pinky finger at the moment.

[Windsor]

New 2x4x3/16 frame rails are 6ft long. 8 foot section to be used for rear crossmember, and bracing.

[Windsor]

Sorry above pics are sideways. Have to insert them from another site.
My mouse/squirrel exterminator. Doesn't like to let me work.

[Windsor]

OE body mounts are cut off and smoothed down. I notched the frame for the 2x4 crossmember that will be welded in. I picked up some 2x1/2" flat stock that will be stitch welded to the top of the 2x4 then milled to fit snug inside the boxed frame.
I'm trying to figure out if it will be okay to cut some holes in the side of the OE boxed frame section and do rosette welds to the 2x4 rails.