I had a 2002 Expe, Same engine, 5.4, and 3.55 gear. It was a great TV for our 6000lb+ 27' TT. It did have the air ride. Don't know why that would be a problem. You set the hitch with it off.
It towed the TT all over North, and South Carolina. All over the Blue Ridge mountain roads, and the interstate grades as well. The mountain roads are way more steep then the interstates. We never had a problem, and never ran out of power.
With the hitch correctly adjusted. It had -O- sway with the 27' TT. Did as well as the 2004 150 with the 145" wheelbase. Both do great.
As for the 4 speed. Don't know why that would be a problem either. You would be towing in 3RD gear, right around 2300 RPM at 65 MPH as that year Expe was not designed to tow in OD. Manual will tell you not to. We got 8 to 9 MPG.
It is a great TV