After spending countless hours looking for propane tuning tech, I have decided to make a collection here....
Franz Hoffman seems to be the go-to guy for any technical propane information.
http://franzh.home.texas.net/
Impco 425/"E" Tuning Info
http://www.rasoenterprises.com/index...tion&Itemid=48
Recurving Ignition Advance
http://www.rasoenterprises.com/index...tion&Itemid=48
Initial Timing Tech
http://fuelsforum.rasoenterprises.co...=822&hilit=425
Timing and Vac Advance Tech
http://fuelsforum.rasoenterprises.co...opic.php?t=130
Seat of the Pants Ignition Timing
http://fuelsforum.rasoenterprises.co...ilit=425#p5786
Tuning Turbo On Propane Tech
http://fuelsforum.rasoenterprises.co...9&hilit=tuning
Carcraft article on tuning w/ wideband O2 sensor
http://www.carcraft.com/techarticles...ter/index.html
Dyno Tuning Chebby 4.3l on propane
http://www.evolutionmachine.com/inde...ane-questions/
Timing Discussion over on Pirate
http://www.pirate4x4.com/forum/showt...523&highlight=