Rogue,
I'm not at my house right now so I can't go out and do a measurement, but 10 feet might work. Keep in mind, however, that you will be using a counterweight most of the time while you have the FEL on. That's going to add significant additional length. I've noticed you've posted an inquiry a few days ago regarding counterweights. Sorry I didn't respond then. The general sentiment seemed to be that using an implement for a counterweight was more cost effective than buying a counterweight device.
That is true, however, a tiller or box blade will stick out pretty far - certainly adding more than 10 feet total.
I bought a New Holland weight bracket that is mounted on the 3PT hitch arms. Holds up to 7 - 50 LB weights and adds only a few inches to the total length of the tractor. I started with 200 LBS and found that was too light for some jobs. I use 300 LBS now and I keep that mounted all the time instead of my tiller.
On 5/19 I posted the info on where I purchased this, part numbers, prices, etc. Here's a repeat:
My dealer purchased the bracket from North State Sales. I don't know if this part number is NH or North State, but here it is.
The bracket is part number 7001 - I paid $94. The part number for the weights is 3113 - I paid $39 each for those. The bracket has this information on a label glued on: North State Sales, 2204 N. Church Street, Greensboro, NC, (336) 275-9578.
Hope this is helpful.
Frank