Until the nylon blocks arrive, I'm still tinkering around with the installation hardware. The initial issue was: What do I do with the two bottom legs of the stock intake manifold now that it's hanging two inches farther off of the head. They're just floating out in the air...
The mounting hardware for the spacer itself is pretty straightforward. M8x1.25X100mm threaded rods with M8 12mm flange nuts.
I was going to make 2 inch spacers out of tubing to slip over the two bottom threaded rods, but instead ordered heavy barrel nuts that will do the job much better because they're fully adjustable.
With the barrel nuts spun onto the rods, it will be possible to position the manifold at just the right attitude in relation to the face of the intake ports on the head. Then tightening the two lower flange nuts will securely pin down the lower legs.
There was another mounting issue with the threaded rods. The angle of the upper rods holding the spacer and flange, and the two lower rods for the lower feet do not
extend out from the engine at the same angle. The lowers are out of alignment with holes in the lower manifold legs by about a 1/4 of an inch. So after the two lower rods have been fully
inserted into the engine block, they need to be bent upwards slightly to engage the holes properly.
The rods are just mild steel and will readily accept a bend without weakening them. The barrel nuts will help as they can be used to protect the threads while the rods are bent. The most simple method would be to use a length of 1/2" inside diameter tubing as a lever to bend the rods. It doesn't take much, as all you need at the end of the rods is a 1/4 inch of deflection.
Accessing the two lower points of attachment poses difficulties as you can't get to from either the top or the bottom. However, removing the driver's side front wheel really helps a lot as you can work from the side through the wheel well.