Diesel Fords I've owned and driven:
#1 NEW 91 F250 2wd standardcab, 7.3IDI E4OD 3.55 posi
good mileage good towing power ran out of steam towing on big hills and in higher elevations.
#2 Used 89 F250 2wd same driveline and gears but had a shiftkit in trans, 2.5" dual straight pipes crossed over to get equal length at rear bumper. slightly better mileage and more power, COOL SOUND
still ran out of steam in higher elevations.
#3 NEW 1996 F250 SC short 4x4 7.3 PSD w/ZF 3.55 posis
even better mileage, unbelievable power and fun to tow a loaded trailer with, I drove it as hard as I possibly could, only mod was to remove the muffler and put a turndown just behind the cat. My friends al loved the 2nd gear smokey burnouts I would do with it. I took the flywheel and clutch out at 42,000km under warranty
excellent power even at higher elevation.(sold it at 3yrs old to buy house
)
#4 very used
1977 F250 SC long 2wd Isuzu 353 6B w/C6 and manual valve body. Dana 60 3.54 open . 33/12/16.5 on rear. towed great if you weren't in a hurry, mileage was about the same as the 91 7.3, but it only had about 135hp and pump was made for offroad/agricultural work.
fun to tow with, avoid hills . sure got a lot of attention though.
#5 1990 F350 SC dually 7.3 IDI w/ATS turbo, E4OD w/shift kit. 4.10s and 215/85/16s. 3" down and turn to a 4" straight through Nelson muffler and 4" turndown. Pulls awesome , sounds awesome not very good fuel economy, but its purpose built/used only for pulling trailer. did headgaskets at 150,000km and used the factory IDI turbo headgaskets.
#6 used 1998 F350 (old style) 7.3 PSD E4OD, 4.10 open all stock except for a turn down behind the cat same as my 96 had. this was a chip truck that I shortened frame by 9' and made it look like a 1984 shorty.
it went like stink, fun to drive but I never changed any spring
, until I got pulled over by our regional police and they went over it for safety
. it got towed on a flatbed back to the farm after I removed the plates and gave them to the nice officer
I would recommend a 7.3 PSD, just not the first year they came out, they used the EECIV electronics and were really hard to diagnose problems.
I have a 5.9 cummins in a 79 ford project truck but haven't put enough miles on it to come to any conclusion yet.
most powerful diesel I drove was a 1990 F250 2wd standard cab 7.3 E4OD, that I had just done headgaskets on . it had a banks sidewinder turbo and other mods to exhaust/trans/intake. it was pretty unbelievable and smoldered tires like it was a blown big block. unbelievable but we did the headgaskets again after another 20,000km , and then again after another 25,000 . so lots of fun but lots of work too. supposedly was pushing 305hp,way past 7.3 IDI capabilities but way cool