You'll probably find a lot more 193s than 083s or 601s but despite all the bad mouthing people give 193s they are a great work truck dd head.better mpg and lowend torque. That's what they were designed for, the swirl atomizes the fuel so it burns better,so you use less ignition timing to light it off. The reduced timing means the piston isn't fighting ignition as long on the upstroke. It's minimum best timing. MBT. Everyone attributes the power and mpg of the the tbi trucks to the tbi,nope it's the tbi heads.
