Slant 6 questions

1970 would still have a points distributor I think. It will start cold and idle better w/ electronic ignition. No rush, but look for a later electronic distributor. I bought a new one for $50 on ebay. Once you have that, you can do the 8-pin HEI conversion, using parts (module & coil) from a 85-95 GM V-8 truck. TrailBeast here kits those parts new or ~$25 at any junkyard. I also grabbed the knock sensor & module which screws in the block drain (w/ 3/8 - 1/4 NPT bushing) and works w/ several after-market engine controllers.