250 six ,sheared crank bolt,options?

[harpo1313]

I just bought this 66. it sat for a good many years so i pretty much went through it.i cleaned the tank ,the lines new fuel pump ,filter and cleaned the carb,points,cap rotor and plugs.
It fired up ,kinda rough at first but after some adjustment it smoothed out.I found alot of slop at the crank pulley.After checking things out i found the crank bolt was missing.upon looking closer noticed it was broken off inside,with a drill hole on an angle into the crank itself ,not much but enough.I lifted the motor slightly in the front to get a correct angle for the drill to be level with the crank to try and drill it out for my easy out,I heated it ,waxed it many times and no go .
From the looks of it this has been an issue with this motor for some time as the keyway on the crank and pulley are toast,and the fan belt has been holdin the whole mess in place.What are my options.Just thoughts ,But can the balancer be drilled and tapped for a grade 8 ,coned setscrew,with the crank having a landing drilled out to lock it in ,one on each side? This truck will be getting a fresh motor hopefully next summer so i dont want to pull it now ,just drive it localy and do my bodywork on it and save for some susp upgrades. Any thoughts Thanks Ron