I had a 88 7.3 IDI 5 speed. Good truck but I drove my buds 89 dodge 5.9 cummins and it convinced me, when the time came, to upgrade to go cummins.
The IDI even with turbo can not run with the 5.9. Comparing apples to apples (if that's possible) 94 IDI turbo stock to a 94 5.9 cummins stock, the 5.9 out pulls every time I don't care what the load. Now granted in 94 cummins already used the p-pump vs the earlier VE. Even the 93 cummins with the VE pump will outperform the 94 IDI in my opinion. This would be in stock configuration, start playing with them and the 5.9 will be the clear front runner.

Now as far as the rest of the truck, Dodges biggest downfall IMO was that they did not offer a crew cab, the extra cab did not have much room in the first gen and finding a 1 ton series single rear wheel is close to impossible.

 

Im goin a different way then IDI or Cummins. IH DT360 is the best of both worlds, although heavier.

 

Cummins offered their motor to Chevy but they didn't take it. Cummins even offered to make a five cylinder for Ford but Ford went with Navistar instead.

Hindsight's 20/20.

 

Thats a new one for me. The articles ive read point towards Ford was going to go with cummins then decided that a V8 would be a more viable platform due to the larger powerband (i agree) so they decided to go with an IH V8.

I disagree with stock to stock a 5.9 winning. My NA 7.3 was able to hang right with my brothers 24v empty. Even the engine ratings give it away, VE engines were 165hp the 6.9 was like 170, 7.3 180 NA. Ive driven a few VE engines, all of them fall on their face at 2100, they cant get "under themselves" so to speak, you cant stay in the power band.

 

http://www.turbodieselregister.com/i...insHistory.pdf

I'll agree that a stock 12 valve isn't any better than an IDI. The thing about the first gen cummins is though, it only takes a timing bump and a turn of the screw to blow an IDI out of the water.

 

i disagree.
back when my 88 was a year old one of the guys at that job bought a dodge diesel. he swore up and down how great it was, until i showed him what a turd it was.
then i put a turbo on my 88 and really showed him what a turd it was.
both trucks were 4X4 with 5 speeds and 4:10 gears.

1989 navastar 7.3 liter na diesel: 190 hp and 388 ftlbs torque
1989 5.9 6BT cummins turbo diesel.: 160 hp and 400 ftlbs torque.

now take the turbo off that 6BT and "make it equal to the 7.3" and the 6B cummins only makes 120 hp.

at 496,000 + miles, my 88 will still walk all over most of the dodges here that have not had 4 or 5 grand put into the engine.

 

Turn the screw on the cummins and you see nothin' but the taillights.

The only replacement for displacement is boost.

 

Ill have to disagree there to some extent as well, yes it is stupid simple to gain a fair bit of power with a Gen1 but that puts you at around 300bhp in other words, the same as a maxxed turbod IDI. More than that the pump tries to run away on ya and the H1C is no match for that amount of fuel, especially without an intercooler. Theres a 90 F350 on our ranch with a gen 1, cranked pump, hx35 and 3k spring. My 92 can walk it simply because his cummins has no nuts over 2k it just stops pulling... sure it will rev higher, but around 2600 it starts trying to runaway. Loaded, i have no doubt he would trounce me.

As ive said before, each are suited to their own strengths, but all in all i say theyre even, especially when comparing a gen 1 to an IDIT, as the IDI's only real disadvantage is being NA. If i always had a trailer on, i would buy a cummins, but as i normally do not have a trailer, yet do pull with it, i find the V8 has the all around performance that i prefer.