ON EDIT:
Didn't notice that the job was done, until after my post. Picture looks good. Glad it worked out all right.
Unfortunately, a 3' addition to the ramp length will make no difference at all.
JayC
Hate to disagree, but done properly (as I KNOW he would), it would indeed make a difference. The difference being the height, not the length. Simply dove-tail the ramps so it can climb sooner. Might consider adding the extra 3' at the front of the ramp, instead of at the end. That would allow you to control the angle that it hits the trailer at, when it arrives at the trailer. As long as the rear tires are on the ramps, when the ultimate height is reached, it is do-able. Seems you mentioned ramps 4' plus the 3' gives you one more than is required, at 6'. Did I miss something?
Putting a block under the landing gear and taking some of the slack out of the truck suspension might give you an inch or two at the rear of the trailer.
If you lived near here, I could fix the ramps with my welder in 59 minutes, instead of an hour. (just kidding, probably take me an hour to get set up, lol)
Dove-tailing the rear of the trailer isn't as bad as it sounds. Probably half a days work to do it, plus painting.
David from jax