Glen,

I don't want to interfere too much w/this JD thread. But, I want to add my 2 cts on installing another brand into your JD tractors.

Last yr we had a Trimble AutoPilot installed in JD 8420 using our AL Insight display. Starting from scratch, the job was slightly cheaper from Trimble than using JD. You can use the JD steering valve w/the Trimble if you already have it. You can purchase the Trimble valve if you don't. HOWEVER, JD is/was throwing in the valve (= JD autotsteer ready) in the form of a rebate that makes using the JD valve more sense...if you don't already have the tractor. Trimble guys say it makes them no difference, valves work the same. Some dealers will give credit on a trade-in for valve, some won't. That may change.

Again-not to interfere w/this JD thread, but we're very happy w/the universal applications of the Trimble stuff. Same goes for Trimble autopilot in JD combine.