Here are the finished aluminum ribs made from the CAD drawings. They were laser cut out of ¼" aluminum plate and came out just as designed. There's just a mill finish on them right now, but I'll clean them up and give them a clear powder-coat before final assembly.
The next photo shows the mounting tabs for the ribs. These were made with 1 ½" x 1/8" thick aluminum tee stock. I made a few jigs for cutting and drilling, and it didn't take too long to turn these out. Each one is bent to fit a specific location on the tilt shell.
The third photo shows how the rib and tab are bolted together. The slots in the rib and the slots on the tab are at a 90 degree angle to each other which gives a lot of leeway for adjustment. The ribs are attached to tabs with ¼" bolts and stop nuts.
With the tilt hinge location verified, mounting brackets made out of 3"x2" angle were fabricated and bolted to the outside face of each frame rail. The frame holes were drilled and tapped, and hex nuts were welded to the bottom of the brackets. I opened up the hinge bracket holes and turned them into slots for horizontal adjustability. I will also be making up some aluminum shims to fit between the frame bracket and the hinge bracket for vertical adjustability.
The last photo shows the relationship between the hinge and the front rib, and how the hinge arms are bolted through the rib.
First photo shows the radiator mounted in place in the brackets. Some rubber strips will be bonded onto the inside surfaces of the brackets to cushion and support the radiator. For the side braces, I decided to use some long aluminum turnbuckle linkages mounted between the top of the side brackets and the frame. They make for a very strong mount without taking up a lot of room. Last photo shows the linkages in place. The linear actuators for the tilt will mount to the top of the frame rails just in front of the crossmember and fit between the radiator supports and tilt hinges.
The revised side brackets were installed onto the bottom bracket and bolted back onto the frame rails. I only installed one bolt on each side so that I could pivot the entire radiator/fan assembly only enough to clear the tilt shell. Once I am sure of the clearance between the top of the radiator and tilt shell, I can go ahead and drill the bracket for the second bolt. I also made a new top bracket that would clamp across the top of the radiator as well. The ends were bent just like the side brackets. Last photo shows the completed radiator support. Also seen in photo are bottom fan mounting brackets. Top brackets will be welded to top support later. It turns out that the only part of the radiator support bracket kit that I used was the bottom channel. The rest was wasted. I should have built the entire thing from scratch and saved some money.
The bottom of the bracket needed to be bent to a 90 degree angle, so I came up with a simple bending brake that I used in a bench vise. I've had success in the past bending narrow aluminum strips this way, and decided to try bending some wider stuff the same way. The first attempt at bending almost broke the vise because of the short sides of the angle bracket I was pushing against. I tried it again with a larger piece of angle for more leverage. Combined with some heat from a propane torch, the aluminum bent with little trouble. Third photo shows finished brackets.