2008 G29 with front end shimmy..... Help...lol

So we just picked up our new to us 2008 G29. It has a 6" lift with new tires and the cart is in mint condition. The problem is after getting it home and driving it thoroughly it has a front end shimmy at top speed approx. 20mph on pavement. If you move the wheel the slightest it seems to fish tail up front. I almost could not control/recover it once while out. The tires say 20PSI and they have that in them. the tires and lift kit are new and there doesn't seem to be any play in the steering. My wife can't drive this HELP! Any advice before trying to return it would be greatly appreciated....

Pics up in a few minutes...