[swarfman64]

The timing with the spacer will advance 3 deg. This may or may not be more suited forced induction. That requires some research and maybe trial and error. It is however a possibility that leaving the timing 3deg advanced is a good place to start without re grinding cams or altering gears. Whatever I decide to run will be based on best opinion & research, measured and documented. There are many theories and they all vary, combustion chamber design, bore, stroke, backpressure etc etc these all play a roll. Bottom line is each engine type is different and each individual modification can alter other factors. Its hard to mix recipes.
The goal for this engine is to give a simple set of modifications and data so anybody can do a 10 psi boost from a good starting point with the minimum of modifications. I feel that decompressing is a must for pump gas and reducing thermal stress on a street engine. I'm using a spacer because it is the easiest and cheapest way for the average player to reduce compression, not because its the best way. If the timing advance is in the right direction I'm inclined to leave it because it will be one less thing for someone with less money and equipment to have to do.