If it's the same as the BL420 I have, then it is a tang drive like this:
Locally made McGee injection was like this too.
You machine a slot in the end of the cam, and drill a good-sized hole in the timing cover. A lip seal is put into the hole. You then make up a drive tang to poke into the end of the cam, through the hole in the timing cover and into the end of the fuel pump. The fuel pump bolts to the timing cover, so the cover needs to be a little hefty. Alignment needs to be within about 15 thou, so not for the ham-fisted like me
.I'm part way through mounting one to a Holden grey motor cam. The timing covers are pressed tin, so I sourced an alloy Tawco marinised cover. It's hefty enough, but pretty rough in the casting. Lots of work to make a crank seal work too. It's in the "not sure if I have the ability to do this" corner at the moment. Alternative is to use the standard pressed-tin cover, and some external bracing.
Cheers,
Harv
