Hey guys for the past couple years I've owned a 1997 F-350 with the 7.3 and ZF-5 manual 4x2 with 3.55 gears and 286k miles. Just recently I retired the OBS and welcomed a 1999 F-350 with the 7.3 and 4R100 4x4 and 3.73 gears with 220k miles into my household. The 1999 is lifted a pretty decent amount like towers over my OBS but with stock size tires. I've noticed a pretty large power difference right off the bat. My OBS seems to be a speed demon next to the 99. I understand I'm going to have more torque with the OBS 5 speed compared to the automatic, and also with the new truck being lifted on small tires. But is that all? Or am I missing something else. Both trucks are stock besides straight pipes, no chips or anything like that. I've also noticed a big sound difference between the 2, the 99 almost sounds greatly better than my OBS. I understand the 99 is intercooled with a wastegated turbo and also has split shot injectors compared to the OBS Powerstrokes single shot (or am I backwards?). Sorry for the long post i am just curious.

 

That post is short compared to some. '99 was a split year so you'll want to know if you have an E (early) or L(late). What's your build date? You are right on the injectors and wastegate but I can't tell you why the new one would be slower than the OBS. The best thing to do is get a diagnostics set up up and running so you can ensure that your truck is 100% and go from there. Does the NBS have any gauges? You can get an OBDII adapter and software is cheap or free depending on what platform you're running on your tablet(s).

 

My e99 was a dog when I got it. No boost over 6-8 psi. Once i fixed my boost leaks it ran 10 times better!

 

Same engine with more oomph, but the Superduty is a heavyweight. OBS gets better fuel economy because of the said weight difference.

 

I am trying to figure out if it's an E99 or L99. I believe the cab was repainted at one point because there is no door jam sticker. And I have the original receipt but the most that says again is just 1999. Any other ways of figuring it out?

 

Does it have 2" or 3" intake manifold openings ? 3" late 99-03

 

Did the L99's have IAH? And I believe that the E's have the powerstroke emblem on the front fender and the L's have it on the door.

 

yes L99 have IAH E99 does not.
i don't rely on door or fender badges , i have seen at least 2 L99 with fender badges

 

Also check the intake piping to see if there's an intercooler. IIRC the early '99 uses the van turbo without an intercooler and the late '99 and up have an intercooler.

 

My e99 is intercooled. Try using the vin yo get s build sheet. Itll have the build date

 

I've been trying to find websites that have this. The only reliable one I know of is Ford ETIS but for some reason I am getting a garbage loading page on my phone.

 

 

I definitely learned something today. I thought these were two definite ways to tell the E and L apart.

I guess it's down to intake manifold diameter, AIH, and spring u-bolts if you can't find the build sheet/date.

 

I have determined the truck is a L99 as the valve cover is stamped April of '99. And on the E99 intercooler chatter, both E99 7.3s I have driven prior to these were both intercooled, both built in mid or so '98

 

Mine has a build date of 3/98 and is intercooled. So I'm pretty sure all early 99s are intercooled, just none of the OBS trucks are intercooled from the factory.