1997 E40D shifting like a 5 speed??

I've owned a 97 F250 reg cab auto 4x4 with 4.10 gears for the past 3 years and has shifted like a 5 speed since the day i bought it. Its shifting patterns are:

1. 0-15
2. 15-25
3. 25-32
4. 32-36
5. 36 +

I know, its geared really low. When it shifts at point 4 & 5 i can feel the torque converter is locked. At 32mph (4th shift) im cruising at about 1100rpm and i just lay my foot right into it (Torque:nod and build speed as soon as it shifts up again whenever I let up on it. I can get it to shift up again as soon as 36mph. I have no loss of power whats so ever and the truck runs 110%.

However when I'm driving normally it always seems to "upshift" at exactly 32mph almost like its splitting the gear. This upshift occurs even when i'm accelerating quick. When I punch it - i think it actually upshifts and then immediately downshifts again to keep up with what I'm demanding from the pedal.

My questions are can any harm result from this? Keep in mind I've been driving it like this for 3 years and never had the slightest problem. I usually drive like a grandma (MPG > Speed) with my foot just resting on the pedal when i drive. I think this shifting pattern helps with my 17mpg average (50/50). I also keep it under 2000rpms on the highway for the most part.

At the same time I plan on adding a tony wildman chip in the near future and want to know if the chip will interfere with my trucks shifting patterns. At the moment the truck is bone stock with just a 6637 air filter. Gauges, exhaust, and chip are all I want to do to the truck.

If I had my choice I'd prefer the way the truck shifts now - I dont street race too often and I like cruising at low rpms. But I want whats best for her. Any thoughts on what could be causing this early TC engagement? I have no CE light, a cleaned EBPS tube, and one meaningless code PO113 (low intake temperature). Any thoughts or opinions would be much appreciated.

Thanks!