Rationale: The boom vang and outhaul are together on SHADES since I like to easily control both at the main thwart, six inches to port and to starboard of the centreboard box. The vang and outhaul are both set up for easy adjustment with lots of mechanical advantage. This involves mounting a number of blocks on both sides and looks complicated but it functions beautifully once the initial aggravation of the installation is over.
 

Lever controls: Our lever is a HA 4192. It is double-sided and has a U-shape when viewed from above. We shackle a triple block to the top corner of the lever. Where the shackle pin passes through the "U" we insert one loop of a ¼"-shockcord (about 12" long with [seized] loops at each end). The other loop goes over the wingnut on the gooseneck to keep the lever from flopping sideways too much. The triple block meanwhile, requires four additional blocks: one on each side of the mast step and one on each side of the centreboard box.
 

The diagram to the right shows the starboard side  arrangement (plus block 2S which will be used for the  outhaul control line). The port side is a mirror image of this arrangement.

The diagram above shows the set-up as both vang and outhaul controls reach their cleats on the aft edge of both sides of the thwart. The double blocks should have their eye straps slightly aft of the thwart along the upper part of the CB box such that the control line under tension will leave the block about 1/8" aft of the thwart. This results in a smooth entry into the clam cleat (CL 211) (or the Lance cleat, mounted with the cam uppermost, which I now prefer). The CL 211's are mounted on the aft face of the thwart (or a six inch piece of 2 x 4 placed under aft edge of a wood thwart). The cleats should angle slightly up from horizontal to conform to the angle of the rope coming up from the double block to the cleat.

Threading the vang control line: We use 5 mil. soft-braid (about 20 feet). Take one end of the line and feed it out through the upper clam cleat on the starboard side. Tie a figure eight knot and leave six inches of loose end for better grip in emergency. Take the unknotted end and feed it through the upper sheave of the double block and forward under the thwart along the CB box. Up through cheek block 1S and through the starboard sheave of the triple block on the lever. Down through 3S and back up through middle sheave of the triple block, down to the port counterpart of 3S, up through the port sheave of the triple block, down to the port counterpart of 1S, back along the CB box, under thwart, into the upper sheave of the port double block and out through the upper clam cleat. Finish with Figure Eight knot and leave six inches of loose end.

VANG NEEDS: one lever (HA 4192) plus prepared wires at each end - one triple block (Harken 086) with shackle and looped shock cord - two double blocks (Harken 084), four cheek blocks (Harken 092), two bullet blocks (Harken 082), two CL 211 clam cleats (or RWO Lance cleats) - four eye straps (Harken 073) - all screws - 20' of 5 mil soft-braid rope

Outhaul Installation: You will need a swaging tool for this (or you could use pre-stretched rope instead of wire).

    The inboard and outboard endplates will have to come off the boom. You will probably already have an entry block at the aft end of the boom, but for this system, you will also need a (small!) entry block on the underside of the boom at its inboard end. I used a HA-6 for this and put it so close to the inboard end of the boom that I had a nasty surprise when I tried out my new system: the gooseneck plug would no longer fit into the boom! I got around that problem by hack-sawing off most of the plug which is now about 2 cm. long (and it has worked fine for the past 20 years!). In retrospect, I like this system because it leaves the outhaul system nice and close to the mast so that the outhaul is not visibly tightened when I let the boom out to a reach or run – which it would be if I moved the entry block too far aft! A really small entry block moved aft a bit might avoid the entire problem, I think. Get the second entry block ready to be installed but do not rivet it in until its rope or wire is in place.
    Deal with the aft part first!! If you already have a wire outhaul, you may be able to use this. Otherwise, get about 10’ (3 metres) of 3/32” 7x19 stainless steel halyard wire, and thread it through the entry block at the aft end of the boom. If you want to reduce the risk of shackle loss, do a fairly tight swaging around the outhaul shackle with the wire end that comes out of the boom. Once you have done this, feed the other end towards the inboard end of the boom. There is a large amount of leeway in its length, the only limit being that it must not be too long. When you stretch the outhaul to its maximum tightness position, the “floating” bullet block inside the boom must still be aft of the entry block at the inboard end, or you will not be able to get full tightness from your outhaul. Once you have the wire at a correct length, drag it out the outboard boom end and swage the bullet block onto its end.
    On SHADES, we use 4-mil pre-stretch for the rest of this set-up. Assuming you have made your wire the max. length, you will need only a metre or less of 4-mil pre-stretch for the other “inside-the-boom” part. Using a small bowline, deadend one end of this line to the inboard end plate of the boom (while it is off the boom!) If you have someone with small, agile hands, you may be able to reach the floating block and thread the 4-mil through it. But most likely, you’ll need to do what I did: Pull the floating block and its wire out the outboard end of the boom. Then take a 20’ scrap of thin line and connect it to the 4-mil by means of duct tape. Thread this through the boom (inboard to outboard) and then through the floating block. If you have near max. wire length, you can merely tie a good long bowline around the sheave of the block and pull the whole mess back to the inboard end where you can untie the bowline and proceed to pull on the scrap line until it in turn pulls your 4-mil through the floating block. If your scrap line or wire is too short for this, you need to feed the loose end you’ve pulled through the floating block, back to the inboard end of the boom (which can be done but is more of an effort!)
Now detach the scrap line from the 4-mil and thread the latter through the inboard entry block. You will be tying another bullet block to the end that emerges from the entry block. Here the limiting factor is two-fold:
1. you don’t want any more rope than necessary hanging out of the boom here but
2. there must be enough rope to permit easing the outhaul as much as you will ever want to
In my opinion, the rope hanging down from the front of the boom should be about 18"  long outside the boom when the main clew is pulled out to its maximum outermost point.
    The block attached to the end of this rope is the mid-point of the outhaul control line system: feed the control line through and then thread the starboard side loose end through 2S (see vang diagram) and then aft along centreboard box, through the lower sheave of double cleat at thwart (below vang control) and then out through the lower CL 211. Finish with Fig. 8 and six inches of loose end. Do likewise on the port side. On SHADES, the outhaul control line is about 15’ of 5-mil soft-braid.