ImpulsiveJames
Member
The only difference between the older 580's are rotary valves, jets, and timing, right? Does anyone upgrade, for example, old SP motors to XP motors or anything like that?
Slightly more advanced question, 580s share the same crank case as....657s, right? Is it possible to replace be jugs and get more displacement easily?
Just curious
Slightly more advanced question, 580s share the same crank case as....657s, right? Is it possible to replace be jugs and get more displacement easily?
Just curious