Thanks for all the comments, I appreciate y'all following along!
More metalwork on the cab. The firewall had a lot of extra holes to fill in. It'll have a hydraulic clutch and an aftermarket wiring harness so none of those holes were needed anymore. I made a bigger panel to fill in a bunch the smaller holes instead of filling them individually.
A notch had been made in the firewall seam for clearance around the new engine. I tacked the two layers together to keep them from flexing or separating so the seam sealer won't be upset later on.
Determining a radius.
Radius and allowance for the flange scribed into a sheet of metal.
Flanged formed using a steel block and mallet initially.
Turning a curved flange causes the panel to distort, so I used a section of round bar in the vise and a hammer to stretch the flange out to take out the distortion.
The filler neck hole needed to be shaved. The shape around it was flattened and a bit more square compared to the right side of the cab. I made a quick flexible shape pattern to compare both sides, and it also maps out exactly how much to stretch the new filler panel.
First step was to roughly knock out a dent in the opposite side so the pattern would be accurate.
Two layers of tape. The blue tape is low adhesion so it peels off easily with no risk of stretching the pattern as it comes off. The second layer is reinforced with fiberglass strands so once it's pressed down firmly it'll hold the same length- this is important as it allows the template to retain the same surface area over every square inch after it's removed. That surface area is what shows how much stretch is needed to replicate the panel.
With the pattern removed you sprinkle it with baby powder to kill the adhesive. You can see how much surface area the pattern has, and how the details of the body lines carry over.
I also made marks on the template to locate the filler neck on the pattern. The patterns can be flipped inside out while retaining their surface area.
Vertical and horizontal lines marked through the center of the filler panel area. The pattern on shows the amount of stretch needed, not the exact shape, so a profile gauge shows how the added surface area from stretching needs to be shaped and arranged.
Low spot in the middle- more stretching needed.
Overall shape is now correct.
After rough trimming. Notice how the bottom corner doesn't match up, that's from the flat stamping around the filler neck opening. Using this method of making a filler panel and having the flexible shape pattern ensures that any variance between the two sides is made noticeable so it can be corrected.
Welded in and welds ground down, still needs final planishing.
The owner brought the gauge bezel so I could fit it and lay out the location of all of the switch holes. I used washers with butyl that are roughly the size of the A/C controls, and cut out a few pieces from a worn DA disc in the diameter of the ignition switch and headlight/wiper bezels. This lets me stick them to the dash and move them around where they look best.
We have a strict limit of one F*ord in the shop at a time, can't let word get around that we like working on them lol
I finished up the dash layout today. The second pic shows how welding close to the edges makes the distortion more prevalent, third pic is after planishing to stretch out the weld zone.
Old vs new layout. The ignition switch was moved from beside the cluster to under it, and the headlight and wiper switches were moved over to make room for it. One original hole on the left side was deleted. The right side was shaved and three 9/32 holes were added for the A/C controls. The spacing was modified from stock to more evenly fill out the panel and better match side to side.
Next step on the dash was to figure out a way to blend in a flat spot to mount the A/C vent right in the middle of the very curved location where the ignition switch was. To keep the flat spot flat I bolted two pieced of MDF together and turned them down just larger than the OD of the A/C vent.
After a lot of hammering, shrinking, stretching, and shaping to fit the contours of the dash... a shape started to form around the flat spot. I got started and kept going and didn't take pics of this process like I should've. This is a shape that I wasn't 100% sure how to make since it curves in two directions with a raised center, but I basically started by remembering that the only things you can do to shape metal are to shrink, stretch, and bend... so I tried to use logic and think what would happen to the metal if I stretched this spot, or shrunk that spot and it pretty much worked out into the mostly correct shape.
After most of the rough shaping was done.
Sharpening the edge of the raised area using a corner of the steel block.
Trimmed and tacked into place... noticed the hammer marks, I'll explain these later, but after tacking there was still a bit of shaping to get this to fit the contours of the dash.
This angle shows that I wasn't able to get the shape of the filler piece to match the dash contour 100%, and I kind of gave up after not being able to add more shape to the mostly finished piece. My reasoning for going ahead and tacking it in place anyway was that I could use a dolly that matched the shape of the dash and finish shaping that area of the filler piece once it was held in place... and it worked. After planishing the two panels into a blended shape I finished welding the panel in and smoothed the welds.
Half and half, this shows how far apart the initial tacks were.
Bolt head stuck in the lathe and dimpled in the center so I could scribe a circle to trim out.
The next step was to finish the dash- shaving the glovebox/ashtray/radio and making vent bumps.
Decided to use the centerline of the defrost vents to locate the two A/C vents in the middle of the dash panel. I messed up and didn't consider that there would be A/C vents added when I originally cut the blank dash panel so part of the vent bump was off the edge of the new panel.
Reference on how much the bumps needed to be raised.
Roughed out with a mallet and sand bag.
The table on the new bandsaw had the same radius as the dash panel so I used it and a chisel end hammer to sharpen up the edge of the bump.
Corner vent bump.. lots of shape to fit a bump around.
I cheated and cut a few reliefs in what would end up as the vent opening to help the surrounding metal flatten out easier.
The cab corners didn't have much rust but I wanted to cut them out anyway to make sure the hidden rust was taken care of. The left corner was also crunched and would be easier to straighten off the truck.
Making a patch for the rusty spot.
After blasting- bottom edge is wavy and doesn't match up well with the corner section.
After straightening the flanges.
Brushed with SPI epoxy to seal up the cavity.
Same process on the other side.
Another thing I did was remove the inner roof brace, mainly for access to straighten the roof skin, but also so I can widen it so it can be welded back in on the outside of the roof rail edge instead of the inside. That will let the headliner to fit flush along the roof rail.
The rockers are in great shape but I cut them up anyway...
Stock rocker profile-
I made a cut in the 90* corner, hammer/dollied the edges flat, then flipped the cut off piece down to make a flat face but keep the inner stiffening edge.
After welding and grinding the welds flat.
These panels are galvanized and it's cold enough to not be able to weld with the shop doors open so I pulled out the ghetto welding fume extractor I rigged up awhile back.
Reason for cutting the rockers- the thin rocker lip shows under the door, and since the doors are rusty I'll have to make new door bottoms. After talking with the owner we decided to eliminate the visible rocker edge and lengthen the doors instead. This will clean up the lines down the side of the truck and make for less work since there will be two less gaps to set.
Got both cab corners cut off, blasted, primed, repaired, and welded back in. I could've bought repro cab corners but I wanted to cut these out higher up to make access to the back of the welds easier, plus all the body lines are already in the right place on the original panel so going back in everything lined up exactly.
I made a new lower section to weld in.
I used a steel block and a chisel shaped hammer to make the drains.
New panel welded in.
Found a spot with filler...
Minor damage underneath.
Welded back in.
The last detail on the cab corners- The inner panel flange stuck out past the outer panel, so I ground the edge of the inner down flush with the outer.
I pulled the doors out and went ahead and cut the door bottoms off to prepare for fixing the rust and lengthening the inner flange/outer skin. They turned out to be in pretty good shape with only the easy flat areas needing to be replaced.
My next step will be getting the cab back on the frame, along with repro fenders so I can shrink/stretch the door skin and fender into one constant shape front to rear, then I can base the shape of the lower inner door frame flange off that shape. I'll also need the door and fender on the cab to set the length of the inner flange so the bottom of the door matches the bottom of the corner and fender.