My personal taste: if you assume that head capacity is limited to some product of displacement (obtained by stroke change) X RPM, I'd rather use the longer stroke and keep the RPM down. Many $$$ worth of valve springs last another season, etc.
The math: stroke length X +10% increases displacement by (duh) 10%.
Increasing peak RPM by 10% gives the same product, but increases inertial load by 110^2, or +21%.
Hmmm. Definitely food for thought. But is 7,500 rpm considered a lot of rpm by todays standards and technology? Are there beehive springs available yet for my application to keep valve train weight and inertia down? Any other weight saving ideas? For instance, my lifters look like they are solid steel. I have seen some that almost look tubular. Are there significant weight differences between lifter manufacturers?
