LA360 Hydraulic Roller Towing Cam

I've not ever run any propane so take this with a grain of salt. Your SCR looks to be pretty low for propane, so you gotta make up for it with a lower duration cam. Plus your gearing is all setup for lower RPM's. I'd be going for no more than the Crane 699601 for torque use, and lower duration if I could get it; it'll help pump up the DCR. Keep the LSA to 112 or more. I used to run a 192 @.050" hydraulic flat tappet cam with 114 LSA for economy and torque (in a gas V8 and 3.08 rear gear).

To quote on AFR: "The stoichiometric air/fuel ratio for propane is 15.5-to-1 compared to 14.7-to-1 for gasoline." So if you are tuning to gas engine AFR, you may be tuning a tad too rich for propane. Could 'splain some of the fuel use but most is in the cam and LSA IMHO.