I wanted the fasted possible engine I could put in this but didn't like the use of the XL engines cause I got cored to easily. Saw a few other builds like this and had this take on it. STD 290 engine with FF, ES and DHS upgrades. Wish I could squeeze in AMS or another DHS but would take to much of a sacrifice. Less firepower than other builds out there but more mobility and less chance of getting cored due to STD engine. Works for me at least...