Needed to raise the front of the frame so that the engine cradle from the Grand could bolt in and still keep stock height. Only had to come up 1.25" so made a cut in the frame at the existing bend where it rises up from under the floor at the firewall. I didn't cut all the way through so I wouldn't get a sharp bend.
Placed it in my press where it needed little pressure to close up the gap which had been already bevelled to a allow full penetration weld.
Ground smooth and you can see it retained the stock curve. Also did the same at the back of the frame as needed an extra 4" rise over the rear axle. The original bend after the cab and over the axle were tightened 7.5 degrees to get the rise I needed.
Showing the full penetration on the back of the frame. The round spot off to one side of the weld was where an old rivet hole was welded shut. Next photo shows the laying out the fish plate on the opposite side to which it will be installed. This is the way I do them using the Government Street Rod Manual as I guide and what I was taught working in the structural steel industry. Only thing changed is the radius on the ends to remove a possible stress riser there. It needs to be of the same material thickness as the parent metal of the rail, 4x longer than the height of the rail overall. Half of it will be without taper with the remaining 25% each side tapering off to a radius 25% of the height of the rail. So in this case the rail is 4" high so 16" long with the taper on each side 4" long to a 1" radius. I just use a socket to draw around. The reason for the taper is so that there is a gradual increase/decrease in stiffness in and out of the bend. This stops stress risers from occurring. Same reason for rounding the ends as well, a point would cause a high stress concentration.
Used the old frame rail from the 58 Willys to cut all the fish plates. The old holes will be useful as plug welds in to the frame. All rust was removed from where the plates were to be welded in and coated in weld through primer to stave off future rust.
Then the rest of the inside of the frame had all the surface rust removed along with any old paint before it got treated with the high zinc weld though primer as well.