HEY ROB ,,FIRST IF THAT HEAD IS THAT NEW YOU SHOULD HAVE A MORE EVEN COMP READING 140 TO 175 IS PRETTY WIDE FOR A NEW HEAD , EVEN THOUGH IT MAY RUN OK,I DON,T THINK YOU HAVE A HEAD GSKT PROB, THIS IS GOING TO BE TRICKY TO DO, I HOLLER AT PEOPLE ALL THE TIME FOR DOING IT BUT YOU HAVE TO BE VERY CAREFULL, WHILE THE ENG IS COLD PULL ALL THE PLUGS AND COAT THE THREADS WITH ANTISIZE BE LIBERAL , YOU CAN WIPE IT OFF LATER , PUT EM BACK IN AND START THE ENG AND LET IT WARM UP TO NORMAL TEMP NOW CAREFULLY PULL THE PLUGS OUT , ALL OF THEM AND SCREW IN AN ADAPTER THAT YOU CAN PRESSUREIZE EACH CYL TO AROUND 150-160 PSI THE HIGHER THE BETTER , ONE CYL AT AT TIME ON TDC PUT THE TRANS IN FORTH GEAR ,SO THE ENG WONT TRY AND SPIN OVER , NOW WITH THE RAD CAP OFF AGAIN BE CAREFULL , SEE IF YOU CAN HEAR OR SEE ANY BUBBLES OR HISSING COMING FROM THE TAILPIPE, INTAKE SYSTEM OR SEE IT IN THE RAD NECK , IT REALLY SOUNDS LIKE THE HEAD IS OPENING UP AND PRESSURISNG THE SYSTEM WHEN IT GETS HOT, THE HEAD GSKT WOULD NEVER LASTED THIS LONG IF IT HAD BEEN MISS INSTALLED , YOU WOULD HAVE OIL AND AND WTR EVERYWHERE, ALLSO WHEN YOU FILL THE SYSTEM BE SURE THE HTR VLV IS ALL THE WAY TO THE HOT SIDE THIS CAN CAUSE AN AIR POCKET BUT I DON,T THINK THAT IS YOUR PROB, ESP WHEN IT HEATS UP THAT FAST AND IS OVERFLOWING THE CATCH TANK, ANOTHER THING HOW OLD IS THE RAD CAP , IT SHOULDNT, MAKE IT RUN HOT ,BUT IF DEFECTIVE IT CANNOT CYCLE BACK AND FORTH TO THE RAD LIKE IT SHOULD, PUMPING AIR INTO THE BOTTLE AND PULLING FLUID BACK IN , BE CAREFULL AND DON,T GET BURNED . FOLLOW MIKES ADVISE ABOUT THE THROTTLE OPENING JERRY