CHuck, if it were POSSIBLE to do the OS 1.60 (it would need a needle bearing con rod), the power would be probably 30-40% less than we get with glow. That would make it sort of an MVVS 1.60, so why not just run one of those, as it is at least purpose-designed.

"waiting on the ZDZ" - WHY ? It will still have a Bing or Tillotson carb (both gave me enough nightmares that I swore OFF the ZDZ), and you'll need to run a hellaciously-large pipe to benefit of tuning.... Yes, you'll have gobs of power, but carving up a bird for a 28" pipe that is 2"+ in diameter.... well... I'll let someone else pilot THAT setup.

[Yes, Dick - I know you're "listening" ]