Hi,

I've always heard that choking down the diameter will give you a better top end, but a lower static thrust. I really don't think that older kit is going to be able to get off of grass unless you have a lot more room than 300' AND the grass is super short. The older inlet design made the plane not want to develop any real thrust until it reached a certain speed on the deck. I had one, and you could plainly see the plane suddenly hit that power band halfway through your takeoff run. I think the grass is going to keep that power-band moment from happening in less than 300'. You might end up in a situation where at the end of the 300', you're yanking back on the stick, and she pops up in ground-effect then stalls onto her back and splats. I hate telling you this, but that's what I think.....