Rev counter sender

[tafftunk]

I picked up my hilux without a going rev guage done all the search's done all the recomendations and have found out that the sender on the pump isnt even on it. Its not a japanese pump and i can see where the little hex sensor screws in but its impossible to get it in there as the block is hard up against the pump, Question is do i have to pull the pump off to get it on if so is there other options, Like pulling apart the alternator and running a wire from that to my rev counter in my dash my brothers an auto sparky he just doesnt know if the rev guage will get the correct signal and work thats all, Other wise its a huge job taking the pump off and arnt really looking forward to that any help would be awesome thanks