You may want to play with the 9x7 or the 9x8 for your 6000' elev,,, may not be enuff pitch with the 9x6 at your elev. You may also want to lose that stock head shim and replace it with the .005 shim from
www.pspec.com,,, another suggestion,,, replace that stock tank with a Tetra 4oz bladder tank for Race day,,, the 5 and 6 oz are ok but your just carrying extra fuel for a 10 lap Race. Reason for the bladder tank is for the constant FOAM free-NON contaminated fuel from the exhaust-fuel supply to the engine,,, in other words your getting a fresh fuel supply to the engine all the time.
As for glow plugs,,, Mc Coy #9 is what was used when I was calling for Gale when we set Fast times in the 1.27 range on the long couse at the Basin and Medferd
BV