A multi-spark system or HEI conversion is all I'd consider. With multi-spark you can retard your initial timing ~ 4 degrees to reduce "negative torque" gain mebbe 2% better fuel economy. Faster starts, fuel economy is about it. The benefits of either are very small for the amount of work and money required.

www.designedtodrive.com

https://slantsix.org/forum/viewtopic.php?t=15779

http://www.rowand.net/shop/tech/MoparHEIConversion.htm