The radiator mounting and battery trays are different from 65 to 66 as well as 61-4 also...
61-4 2WD trucks battery is mounted on the firewall next to RH hood hinge.
65 is the tray with 2 triangular brackets which mount to the core support..two of the inboard bolts goes through the radiator mounting bracket on the core support. The outboard bracket has 2 bolts which bolt to the main core support There is also a bolt/nut that goes through the fender apron anchoring the actual tray to it as well.
66 is the same as 65 except there are no bolts/nuts that goes through the radiator mounting ear...no ears to go through...instead the inboard tray bracket has 3 bolts as I recall which bolt to the core support in the same fashion as the outboard bracket on the 65 tray. Theres also the bolt/nut that goes through the tray and fender apron as in the 65 trays.
And you will need a 65 battery tray too as theres no nutplates on the inboard side to accomodate the 66 tray as the 65 inboard bolts to the radiator mounting flange that got deleted in 1966. Theres also 2 stiffener brkts used on 65 for the radiator mounting ears/brackets which also were deleted in 1966 too.
I wonder what the difference is between the newly offered 65 support and the 61-64 that's been re-poped for a while now. I'm thinking the 65 still has the round inner fender mounts and the same radiator mount as the 61-64, so what's the difference?
I bought a 61-64 support last year and modified it for my 66 2wd. It took a few hours to transfer the inner fender mounts, remove the radiator mounts, and to drill new holes to mount my radiator and battery box. Interesting that they now offer a 65 2wd support, but not the 66 yet.
Jerry, I am getting ready to do the same thing you did for my 65 2W F250. I am removing a core support from a 61-64 2wd and want to know what I need to modify forsure. I have the same inner fenders on my 65 as a 66 has. I see what you have listed but do you have any pictures of what you did? This made sense for me because the support I found was in very good shape and the guy sold it to me for 30 bucks.