88 Crew Cab -6ft bed Diesel build

[y5mgisi]

Sounds like a cool plan.

 

[rjfguitar]

Looking at both the cummins and the 7.3, the 7.3 is 100 lbs lighter and comes with more power out of the box. You also cant knock its durability. It really is a great motor. I don't think the mileage is as good as a cummins, but setup right will be good enough. There's plenty of hop up potential and parts around as well.

Unfortunately, B series Cummins power and T444E power seem to be two different things. A B series is considerably stronger at the same HP as a 7.3, my 235HP 5.9 in my 01 Dodge has considerably more pulling power AND get up and go than my 225HP '97 OBS 7.3 truck, with both trucks equally weighted (14K). Infact, my 7.3 has a TS performance flip chip that bumps me to 275HP, making it feel pretty similar in get up and go to my 235HP stock cummins truck. But.... when I bump up a couple numbers on my Edge Juice in my Dodge, it's no comparison. The way they respond to power upgrades is different too. My 7.3 with a chip just felt like a little bump in power, my 5.9 trucks with a chip feel like they have twice the torque.

It's all in the torque curve with these two engines. The torque comes on quick and almost violent like when the turbo lights at 1300rpm, with a 5.9. The 7.3 struggles under about 1600rpm, and the torque comes on much slower and softer. The later super duty chassis 7.3's are a little better, intercooled and wastegated turbo, but the V8 configuration still doesn't deliver the torque like a B series does.

With all that aside, I applaud your plans. The 7.3 IS a great engine. Above 2KRPM and they really can bring on some power. It is definitely a more complicated swap, with getting the IDM and truck's PCM swapped over and programming. I would run an E40D though, I personally think an automatic is a better match with a 7.3, simply because the torque just isn't there with them and the autos help keep them above 2Krpm and in that sweet spot. If it has to be a stick, I say your ZF6 is a good choice, I have a ZF5 in my '97 F Super Duty 7.3 truck and it sucks. Too big of a split between gears, and slow to get moving leaving a stop in 2nd gear. I have to let mine rev out pretty good so that it's not climbing out of an RPM hole when I shift.

You probably already know most of this, but one drawback on the early OBS 7.3's is the injectors. They are pretty small, and will pretty much only allow enough fuel flow for about 275HP, or call it 50+HP on top a 97 programmed 225HP truck. Once the stock injectors are changed out, the turbo becomes the next issue, and after that the bottom end becomes an issue at around 400HP IIRC. Most guys will put studs in on the mains and rods IIRC, and then the bottom end is good for another power increase.

 

[79k20350]

I appreciate the info. Most i've picked up already.The last week or so has been heavy on the research. Overall I'm looking for a solid tow rig/ daily driver. There are people making a TON of power out of these motors so I'm sure hitting my goals wont be an issue.

For motor upgrades im looking at:
D66 turbo
Stage 2 injectors
Intercooler
Fuel system upgrade
Computer tune

Nothing too crazy but this should put me in 350 range with some room to push it to 400 pretty easy. Should also help the low end quite a bit. I'll prolly just start with an impeller in the stock turbo until I can afford to upgrade to the d66, but the rest I'm going to do as it goes in. Depends on cash. There's other things like adding bellows to the up pipes that I'm going to do. Plan is to strip the motor, clean and reseal it and if its not too expensive stud it.

Whats nice is I have the entire truck. So wiring/ computer stuff should be easy. I cant imagine it is any more complicated than an ls swap.

I've set my sights on a 4r100. Probably a John woods. Do it once, do it right. I'tll shifter way tighter than stock and come on much quicker.

Drivetrain is going to be 4r100/205/ 4.10's on 35's. Should be a good choice for pulling and cruising.