O.S.18 TZ info
 

I am planning on getting this engine and running it in a drag car. Will use high nitro (50%). What numbers should I run such as head clearance and which OS turbo plug? It comes with a P3 plug which is a super hot plug and they say it runs well using 20-30% nitro. Should I step up to a colder plug running the 50%, maybe their coldest plug, the P8? Any help or suggestions would be appreciated. Thanks.