I dont see a reason it would drop fuel pressure only in OD.

OD is a high load situation, especially with reduced gearing from the tires along with the extra weight. High load could be making a plug/coil issue rear it's head if they're a little weak.

I googled Forscan and misfire count, it looks like it is supported (A guy with a 00 expedition said it didn't work on his but a guy with a 2002 it does). If you cant get something like the Torque App to show misfires Id buy the $30 OBD2 unit on Amazon and put Forscan on a laptop (Forscan is free, just renew the license every couple months). It doesnt show which cylinder has the misfire but it will give a misfire count from what I saw

 

Dude at orelly's told me last time i was there they had nothing that would work..tried to sell me just the connectors..which showed he wasn't listening. The line is nylon with the connectors made into it. It says my local store has them in stock and a couple of the reviews where owners of same model and year. ill go by there this evening and get a set. So thanks......
I ordered a Thinkcar Thinkscan SR4 OBD2 scanner off amazon. Not sure of the quality but It'll work till i can get a better one, hopefully it'll help me fix this issue.I totally get what you are saying about the big tires etc.soon as it goes into OD it feels like going from 1st to 4th. Or 4 cylinders cut out. surely a 4.6 can cruise at 70 even with 33's. (Triton..what a terrible motor design) ill never own another.
Another question. Could a vacuum leak or manifold leak cause it..theres no codes no noises just the slight shuddering when maintaining speed and 65mph top speed..it screams coils, plugs, pigtails. When i figure it out and i will ill post it and end this thread.

 

If they have the correct end fittings you could just buy a section of fuel injection hose there and make your own... It a very stiff rubber hose you push the ends into and presto. Sometimes you have to heat the ends up in a cup of hot water to soften up enough to insert the fittings..

Then change the spark plugs.

 

It's a nylon line with rubber around it..the ends are made into it.i was going to just replace the ends and after peeling the rubber back I decided i just couldn't live with it patched together..if it comes down to it ill just order the connectors and Fab my own from tank to filter. Would running and extra ground wire help. Ive read the tritons run better when a large gage ground is added to stock.
the more i drive it and think about it I'm leaning more and more toward coils/pigtails and plugs..a TPS problem would happen the whole time.must have gotten a bad coil or the guy messed up the plug wire