this engine will see moderate nitrous use (under 200 shot) about 25% of its runs. the truck runs on motor for the first three classes then gets sprayed in open class. from what you are telling me the tall deck is probably the better option. will the 4.5 crank work in this tall deck ( i had been told by one shop 4.25 is max in these blocks) if it will work i will buy a 4.5 crank.