What would be the easiest, cheapest and quickest way. My son eventually wants a 340 but for now it's to hard to get timing set and it doesn't seem to run quite right. Motor just rebuilt and I kited the carb but it just still wants to fall on it's face on take off and low speeds. I thought it was like a power valve issue but not quite sure what type of set up on a one barrell.'73 was the first year for electronic ignition across the board. You should be safe ordering parts for any slant from '73 to '76. You will need an electronic distributor, a ballast resistor, and a wiring harness if you go stock Mopar. You could also buy a Pertronix Ignitor, swap it into your distributor (replaces points) and go on down the road.
A ready to run distributor for the 273/318/340/360 will fix you right up. They can be found for around $70 and are a complete drop in replacement for your old distributor. You can leave the ballast in place and you don't have to re-wire anything.The electronics are built in. It really woke up my stock 318. You may have to invest in some new plug wires as well with male leads for the net dist cap. A set of universals can be had for $15. You just have to put on the ends.
This is the one I installed.
http://cgi.ebay.com/ebaymotors/MOPA...r_Truck_Parts_Accessories?hash=item4cec11b867