Understroke to 90mm and REV IT! Combine with 83.5mm bore cylinder bore for 1970cc displacement vs. standard 1984cc. Or, go all the way to 84mm and get 1995cc (and very thin cylinder walls, too). This will be a party at 5k rpms to 7500+.
With the correct pistons and rods, you'll produce an amazingly flexible fast road, race, or rally bottom end that's all business. Run high compression, improve the cylinder head, and install cams like 268, 276, or 288. Make sure that transmission ratios are tightly spaced and short.
This one fits the 038, 06A, 06B, 06D, blocks, etc. Stroke is 90mm stroke and journal size is standard 47.758mm.