usually propane powered engines timing is set a few degrees early... if you can find a local propane distributer. that sells or knows a installer. they will be able to give you the correct settings.
if you ever need to remove the heads, have them shaved or do it right ... install high compression pistons and rods... 12:1 would be a good place to set the engine up for, as propane has 105+ octane....
the higher compression will give you more power and mileage...
'83' 2.2 diesel Ranger
'56' F100 project
(crown vic front suspension, mark 8 - 4.6, 32 vlv - v8.
rear end 'to be determined' .. mark 8 or cobra..)...