MSD Dual Curve 40672 LPG CNG MAF Timing advance unit for Propane redoes timing Autronic Controls This amazing box  will advance  timing so at full advance a lot earlier  which is whats needed with LPG  while allowing easy starting which is not going to happen if you  just wedge timing weights or lock them out- gives far better MPG  and power  to your motor ,a real asteal at these discontinued parts - grab a bargain will fit virtually any car  V8 or UK  running on CNG  or  LPG-  but will fit all others American or whattever- see instructions at bottom of Listing just in series with MAF  sensor on airbox  from what i can make out- !

See also  our MSD 8891 ignition timing with a variable degree switch in the cab!  truly  awesome peice of kit!! adjust  to suit your needes!! call Mike 017738356666  for  more  details  

get a real bargain these retail at over £110  !! see www.dualcurve.com  for all specs etc by MSD  in USA