Made some progress on the F100. Used some 1/2 pipe to hold the frame rails in position. The unused/unneeded holes in the frame irritate me. Especially the one I caused from removing things. Have to weld em up and grind em down.
Prepped left side for hole removal. To do a decent job and not get a bunch of contaminates in the weld, have to grind both sides and clean the barrel of the holes with a carbide burr. Since it is a structural item, I try to repair the holes as good as the base metal. Set welder same as a normal weld of given material thickness. Using a lower setting is easier, but lacks the depth and heat needed. Yes you can fill the back side with cold welds, but still not best practice. I go back and fill the back side at same power to get them to full pool. Then knock the humps off enough that the surface can be cleaned and not cut myself.
Put down acid etch primer on the bare metal. I spent some time cleaning the front of the cab and touched up the paint where it can't be seen when assembled.
With most the holes filled and slicked out, I am finally at the starting point for the first few feet of frame. Then back to swiss cheese at the cab mount. 18 holes in the next 12 inches.
The right side frame rail has additional clearance for the exhaust. The lower flange is bent down, and I cut the top flange to fit the headers. After many hours of deliberating how to reinforce the frame, I decided to box some areas instead of other methods. One area being between the IFS cradle and the rear LCA mounts.
Just welding in a box plate to the downward slope can be done, but will **** to make any kind of radius. Grinding to fit will make a knife edge and welder will liquify it. So I used a big adjustable wrench and bent the lower flange back mostly flat to make an angle joint
Then trimmed it and the flap in front of it to about 1-1/2 to make maximum clearance for the header. Will still have to modify header to fit properly.
Test fit the IFS to see what the fitment would be like as the fame changes width.
Ready to start cutting. Moving front end forward 2", up 1".
Cut a relief 1" up into the frame. This allows the truck to sit 1" lower, and be able to make flat, full width mounting plates to the cradle on the bench. Drilling holes in the bottom of the frame *****. For the transitions I cut a triangle slice out ot be able to bend the bottom up to the new level and keep the radius.
I figured 1" was about the max before the frame needs to be notched for the LCA rea mount.
IFS in it's almost final location
The mount holes in the IFS are not the same width. The forward set are farther apart. The holes are close to the edge of the frame web. If just bolted on, the hole would go into the radius. This also removed some of the contact area of the cradle mount points. The frame really needs to be widened and not radiused, hence the new plates that can be positioned as needed for better fitment.
Bent the bottom flanges and welded up the seam.
Next step is to make the plates and get them installed. Have to decide if I want to sleeve long bolts, or just bolt to bottom flange only. With frame boxed I'm not sure the sleeves will help. Could weld captive nuts, but would be very difficult to replace if needed.
