MOPED ARMY

The spree head has squish band, I doubt your decked head does. Your decked head has big fins, the spree head doesn't. It's a wash, they both will increase compression.

If you want a better answer send me a decked one and I'll compare compression #'s; or just buy a spree head for $10 and you can answer this one.

As a note, with the spree head I saw an increase of roughly 30 psi.

What did you see? Within lies your answer.

Non-scientificly I think you're better off with the decked stock head as you'll sse the effects of heat fade less rapidly thanks to the increased cooling area.

BUMP

I would chose the head that gives you the best squish clearence, and a decent amount of compression. An effective squish band will allow for better burn of the gas mixture by forcing the mixture up into the head. A lot of 2 stroke road racers would rather have a decent squish and reasonable compression with the ability to advance their timing using a cdi curve in the areas of were their porting and expansion chambers are best utilized to make their power. Having a high compression ratio will really make the bike sensitive to weather changes like: temp., relative humidity and also the dew point. It might also have an effect on your tuning, you might be able to tune it very well on the top but the bottom end might be so rich that it absolutly such to drive unless it is wide open all the time. Usually good street compression is around 130psi, it allows you to run normal gas and not have to worry about high heat build up which will lead to detonation.