Interesting, I never bothered to weigh the parts like that. That shows the 30 weighing 1.6 oz. more than the 25. My complete 30 weighs two ounces less than my 25, so I guess the extra time I spent removing metal on the 30 was worth it. I recommend using the 30.

Displacement = ((bore x bore) x stroke)) x .7854

(If you measure in inches, divide by .061 to get cc)

AV8TOR