I ran 59A water pumps in a '32. I went ahead and cut the mounting arms off of the 59A pumps since I wouldn't be using them. The belt runs pretty close to one of the '32 mounts. I had several sets of original '32 engine mounts and one of them had been ground away so the belt wouldn't rub. Just one side needs this done, one side clears fine and one side does not. Then I had to find a hose with a quick offset in a short distance to fit the radiator. I went to the parts store and went through all their hoses to find ones with a tight enough bend that wood fit. Then the tops of engine mounts bolts were hitting the bottom of the hoses. I had to flip them upside down so the threaded side with the nut was facing the bottom side. I had a beautiful original frame, and I didn't want to weld or drill holes in it.
Was this the way to go, I'm still not sure. It's a little mickey mouse; I honestly think the 59A water pump mounts are a better way to go. If anybody does use 59A arms do not mount them flush with the tops of the frame rail. They need mount a little lower to be correct, it's not much, but I can't remember how much they need to be lower than the top of the frame rail, maybe a 1/2" but I'm not sure. I've had a stroke and I've lost some of my stored-up info. If they are mounted too high the back of the intake will hit the firewall. If you're lucky enough to have a pair of '32 mounts you can bolt the engine in using the '32 mounts and then bolt the 59A pumps on, then you can tell exactly where to weld the motor mounts to the side rails.
I bought an unfinished '32 3W. The guy had a flathead with 59A pump mounts welded flush with the top of the frame rail. Then the firewall hit the intake manifold. He had the firewall marked where he was going to have to cut it out because it was rubbing. Luckly, he hadn't cut it yet. A flathead fit from the factory without hitting the firewall!
You guys mentioned the tapped holes being in all of the flatheads for the original '32 mounts, '32 to '53. I have about twenty blocks out in the garage and there is one that never had the '32 mount holes drilled in it. I though they all had them until I found that one.