Could be useful for valvetrain testing, as far as being functional.

It all depends on the application. What works best for drag racing traction, will not be the best suspension design for road racing traction. A multi-link solid axle is usually better for drag racing, but IRS is better for taking corners.

Not sure what the correct heat treatment was supposed to be for the RPM block, and if I was Robert Pond I'd probably offer you a discount on a replacement block.

As for what you should maybe consider the next time you get an aluminum FE, have the block and heads go through a cryogenic heat treatment once all machining is complete. Cryogenic heat treatment brings the parts down to a really cold temp, and then brings them back up to a specific temp and this process might happen several times. The result is all stresses that wind up in the metal from machining and even sometimes forging, are reduced if not eliminated. This can strengthen the engine, and keep this from happening again. Something to think about.

http://www.enginebuildermag.com/2017/03/big-chill-cryogenic-metal-treatment-benefits-may-not-visible-real/

If I remember correctly, Jay was looking into using thinner diameter rocker shafts to provide a slightly higher rocker ratio. This would allow you to relocate the pivot point without redesigning the SOHC head. Considering that he is designing his own SOHC head now, I wouldn't be surprised if this will be a feature of his SOHC heads.

Not exactly surprised. GM Truck Central has an article on some testing they did, made me realize that a K&N filter is not the best idea. You're better off using a high quality paper filter and save your money. The K&N was one of the worst performing air "filters" in the competition. If it was a marine application, I could see an oil based filter being chosen over a paper based filter due to the amount of water that filter is going to be dealing with. The evidence in the engine masters comparison shows that you don't really sacrifice power with a paper based air filter, it has a lot more to do with the direction the air has to travel to enter the engine. From an engineer's perspective, it makes complete sense if you think of flow into a hole, the design on the inlet can have a huge impact on the head loss of that port.

http://www.gmtruckcentral.com/articles/air-filter-study.html

I'd say why risk messing up the cam with sanding it down? Just put the cam in a vat of white vinegar for a day or two. I'd recommend doing this right before you plan to install the cam, as steel parts will flash rust after this process if they aren't covered with an oil.

2. It seemed like the Whipple air to water intercoolers were intended for marine applications, with an unlimited supply of cool water.  I wasn't really sure if it would be effective in an automotive application where, I'm assuming, you'd need a second radiator and pumping system to make it work (if it could me made to work at all).

They were designed and intended for mod motors, as my memory recalls, which Ford has already designed an intake with a built in water to air intercooler. You do need a second radiator, reservoir and an electric pump. To use a whipple, you also need to be running EFI. I'm not sure what your current setup is, which is why I mention it. So this is not an idea someone pursues without a large chunk of cash for a FE.

I was looking at your AFR table yesterday and I was going to type that at cruising (low load and low RPM) I think you should be running more towards lean, not rich. A lambda value greater than 1 is rather common for low load an low RPM cruising.