Hey guys hows it going. Just curious off what the major differences between the 99 7.3 an 03 7.3s are?. Different features horsepower numbers an such. Anything different between the trucks themselves. Changes or such. Thanks for the help

 

Depends, are you referring to an early 99 or a 99.5, because there are big differences between those too.

 

If you look up at the top of this page, there is a gray bar with a button that says "Articles/Specs". There you can find the specs on most of our trucks.

BTW, the '02s/'03s has better creature comforts and a nicer instrument cluster, including a digital odometer that can display some of the things you would normally use a gauge for... I love my '02.

 

Mainly horsepower number an any changes to the engine itself. An yeh tell me the differences between the 99 an late 99s.. What were the major changes from the 94 7,3s to the last 2003 7.3 powerstrokes.

 

94.5-97- non-wasted, non intercooled, 15* HPOP
99 early- wastegated, intercooled, 15* HPOP
99 late-03- wastegated, intercooled, turbo changed slightly, intake plenums on heads got bigger, 17* HPOP instead of 15* HPOP
Somewhere in 01 they switched to weaker, cheaper PMR (powdered metal rods) instead of forged rods in the motor
Those are the major changes.

 

How about horsepower numbers? Whats the function off the wastegate. Sorry just trying to learn. Thanks for the help. HPOP High pressure oil pump. Is that correct.

 

235 hp/505 tq. Wastegate bleeds off excess boost pressure to avoid overboosting. The OBS (94.5-97) have a larger turbo housing and no need for a wastegate. The SD got a smaller housing to build more boost, hence the need for the wastegate to bleed off the extra pressure.
Also, the 94.5-97 have 90cc AA code injectors stock. Early 99 has 120cc AB's. Late 99-03 got 140cc AD's. You are right on the HPOP. Tons of info already in the forums, but with the search not working it's hard to find. No worries, we don't mind explaining stuff.

 

Some differences between Early 99 and 99.5

Credit to Chase aka superduty4x4, Ron aka Ron's Power Stroke and in Bold credit to Jet aka SolidGround

Early 99 has a wicked wheel in it from the factory. And much smaller turbo (spools faster, though)

The early99 has 120cc(AB code) injectors and the late99-03 has 140cc(AD code) injectors.

The early99 has 2" intake plenums. The late99-03 has 3" intake plenums.

The early99 has a 15* swash plate HPOP. The late99-03 has a 17* swash plate HPOP.

The early99 has one glow plug relay. The late99-03 has one glow plug relay and one air intake heater relay side by side (along with early '99 CA models) . Both relays are on the passenger side of the fuel bowl toward the front of the truck.

The early99 has a totally different air intake that is not inter changeable with the late99-03 (except for DRW trucks) . But you can put the late99 air cleaner assembly in the early99 truck. The only three afterarket air filters that work on the early99 are the AFE stage 2, the AIS and the KWIKK 6637.

The early99 track rod has smaller mounting bolts than the late99-03. (except for DRW trucks)

The early99 has shallower rotors than the late99-03. (except DRW trucks)

The early99 has shorter hub-bearings than the late99-03. (except DRW trucks)

The early99 front axle U bolts are square where they go over the spring pack. The late99 U bolts are round. (except DRW trucks)

The early99 has a different pitman arm than the late99-03. (except DRW trucks)

The early99 does not have the AIH like the late99-03. (except CA model)

The early99 does not have the automatic transmission fluid cooler in the radiator.

The early99 has no indicator light showing that "cruise" is on. Late99-03 has a cruise light that will come on when you set the cruise control. The early99 has the light in the dash already. A newer PCM(Yes it will plug in and will run better too) must be used to make the cruise light illuminate. It is a green light on the right side edge, half way up.

 

I'm not as convinced about this. We've seen BOTH PMR *and* forged motors give up at the same HP levels. We've also seen both PMR and forged motors still living today at HP levels above that. I think when you start playing in the low 400HP range, it's a craps shoot, either way. I think both can survive well over 400HP, if some unknown (at least to me) conditions exist.