A magazine some years back (might have been practical classics) converted a J60 engine to civi spec. can't remember what was done though.
I belive that the later 4.2 block from about '68 on is the same as the J60 or rather the J60 is base on the later block
Looks like the same unit as on a Champ assuming that it is and negative earth 1 to 1, 2 to 2, 3 to 3, + power probable goes to ins +/fuel, - negative to R1 neg. Hope this may be of help