I took the road less traveled and used a pair of 850 thermoquads. 18 dyno pulls later they were dialed in. They made about 40 hp more than a 1140 dominator on my 605. Torque numbers were better from the start of the pull all the way to the end. IF I drive it nice, I've been able to see 10mpg. I'll never go back to a single 4bbl. Dave