The coils I bought from ebay a few years ago for my varnish blue 400/4 were too short to fit between the two original coil mounts. Rather than butcher the originals I made up two mounting blocks to fit between the original front coil mounting and the new coils. I bolted the rear of the new coils to the original coil mounts at the back and used the new spacer blocks at the front locating the fixing screw into the origianl coil mount. The extension piece of the new block allowed me to fit the front of the new coil into this. This ensured the tank would still fit over the new coils and all the original cables were still the correct length including the HT leads.