The coupler conversion kit is made so that if you use the 36" wheels, the couplers will end up at the proper height. The Rivarossi wheels shown in your photo appear to be their usual under-size offering. (The wheel diameter is measured over the tread area of the wheel, not over the flanges. However, to use the 36" wheels, you'll need to shave a little material off the face of the brakeshoes which are moulded onto the Rivarossi sideframes. There are four brakeshoes on
each side of the truck - one at the outboard end of each of the outer wheels, and one on either side of the centre wheel. To do this, use a new #11 blade in your X-Acto knife to slice just enough plastic from the face of the brakeshoes that the wheels can turn freely, without rubbing on the brakeshoes.
The large crosspiece at the outboard end of the truck also needs to be removed. To do this, place the truck, right-side-up, so that this area is firmly supported, then slice straight down with your knife, removing only the material between the sides of the area where the Kadee part will go.
As for the "extra" screws, they're to hold the Kadee conversion arm in place. To do the installation, use a #17 chisel blade in your X-Acto to remove the nub indicated by the arrow in your photo - simply shave it off flush with the flat area on the truck. On this same area, use a scriber or similar tool (the point of a drawing compass works well) to make a mark at the centre of this flat area - that is, at the mid-point both side-to-side and lengthwise, then drill a hole using a #57 or #58 drill bit. If you don't have a suitable drill bit, you can get-by with a #11 blade in your X-Acto - with the knife handle vertical to the truck, place the point on the mark, then twist slightly while applying
very light pressure. Flip the truck over and repeat - all you want is a very small opening to allow the screw to "start". It will cut its own threads as you tighten it.
In your photo, the Kadee part is upside down to what it should be for installation in the truck sitting as it's shown. Assemble the couple/spring/cover to the arm, then insert the screw (use the shorter one) from the bottom side of the conversion arm (the bottom is the side with "505" cast on the surface). Tighten it just enough so that the coupler cover is snug to the arm. Now, with the wheelset removed from the outboard end of the truck, slide the conversion bolster into place. Do not glue it yet. Insert the remaining screw through the elongated hole in the conversion bolster and into the hole that you made in the truck earlier. Align the top end of the Kadee uncoupling pin with the extreme outboard end of the car, then tighten the screw. Not too tight!!
I believe that this is Kadee's recommended setting, but if you have particularly tight curves, you may want to loosen the screw and slide the arm so that it extends a little farther. Re-tighten the screw, then try two cars coupled together through the tightest curve where they'll be operated. Adjust the amount that the arm protrudes accordingly. Once you attain trouble-free operation, you can glue the coupler conversion arms in place if you wish. Use liquid styrene cement, such as Testors, or ordinary lacquer thinner.
Wayne
