The Long stroke motor made good power but suffered from destructive crankshaft harmonics...the same with the 2.5 longstrokes.
If you are building a 6 bolt crank engine that runs past 7500 rpm, a 2.6 or 2.7 shortstroke would be my first choices....as the parts are easier to come by and the 2.2/2.7 combustion chamber is small enough to make good compression without too much piston dome.
2.5 SS DC90 Cams 11/1 comp...made 285hp @8500rpm and 21 mpg highway
