Question:
Is anyone interested in aluminum radiators?

Background:
I appear to be in need of a radiator, as it separated into several pieces when I removed the cap, and it is a nice combination of orange and white looking like it leaked profusely and baked antifreeze over most of the surface.

I have not found any new replacement radiators. Koyo actually do Hakosuka radiators, but nothing for any Isuzus.

The only thing I have found is Isuzu-Sports / Eagle Sayama, will recondition the customer's radiator for 63,000 Yen plus shipping both directions. That would be $768 USD, and close to the same in Australian Dollars. I think I can get a new radiator made for that kind of money.

I've looked around at custom radiator manufacturers, and found one that makes formed end tanks, and can do vertical or horizontal flow, with a variety of tank and core thicknesses, and they stress that their products are direct bolt in, with no modification to the vehicle. This is rare, at least on this side of the world, where most aluminum radiator manufacturers use three inch thick end tanks that are made by welding together squares of aluminum sheet into a box with sharp and awkward looking boxes.

I have been looking at the cooling capacity of the original and trying to determine appropriate core and end tank dimensions for an upgrade. Since the state-of-the-art in 1969 was to bolt a big oil cooler onto the front bumper brackets and run oil feed pipes through the front valence, it would appear that the original radiator is not quite large enough.
For the 1969 G161SS engine, I show core dimensions of 270 mm tall, by 485 mm wide, by 30 mm thick, with a volume of 3.93 liters. (This is the volume of the fins, including the rows and air between the fins. 3.930 is actually pretty decent size. Compare that to the original Gemini JT191F 1.6 liter DOHC non-turbo at 3.74 liter, and the original Gemini JT191S 1.6 liter AWD Turbo at 7.49 liter.
I do not know the thickness of the radiators for the G161 regular, G150, G161W, or G180SS. The radiators all look similar in shape, but the 161SS does not have the little wing or fan guard like the GT-R and 1.8 liter GTs have.
My best alternatives are:
A 38 mm thick core (51 mm thick end tanks), which would have a 4.98 liter core volume (27% larger),
Or,
A 57 mm thick core (70 mm thick end tanks), which would have a 7.46 liter core volume (90% larger).

The drawback of the larger size is that the added radiator thickness reduces the space between the radiator and the front of the engine, because there is no space to move it forward toward the grille. The first option would reduce that space by 6 mm, and the second would reduce that space by 19 mm.

Like I said, I think I can get these made for less than the $768 USD/AUD that Eagle/I-S charge for reconditioning a used one. I was wondering if anyone else would be interested if I had more than one made. These would not have the little wing like the later GT-R or 1.8 liter radiators, and would be in natural aluminum finish. And I intend to have a temperature sensor fitting put on the outlet side for an electric fan/EFI. Aside from that, these would be visually very close to the originals, only thicker.