Wes Tausend wrote:
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The odd thing is why would a relatively large displacement such as 7.3L develop excessive EGT's if newer, smaller displacement diesel engines do not also do so under the same heavy load conditions?
It has been my understanding (based on tons of research) that the 7.3L PSD in a stock configuration is incapable of producing EGT's high enough to warrant concern. However, the very minute you install larger injectors, this becomes a problem. More power upgrades from other sources only exacerbates the problem.
There are simpler ways to lower your EGT's without going through the expense of an intercooler. From what I've read, most people are not happy with the EGT decrease after installing an intercooler on their OBS 7.3L, which is one of the reasons I haven't done this. For the work and cost of an intercooler, one would expect more than a 50 degree difference (which is about what most people have reported).
I chose to make other improvements to decrease EGT's, which consequently add more power and efficiency. There are so many things that go into making this engine perform at an adequate level that I have to wonder if those people who report negatively about its towing characteristics don't have their truck running right in the first place.
For example, one of the biggest PITA things to do on these trucks is to replace the up-pipes. However, if your up-pipes are leaking (which is extraordinarily common on the 7.3L PSD), then you will be robbed of power (boost) and fuel efficiency, while unnecessarily running up your EGT's as you pour in more fuel (in an attempt to make more power). Replacing those on my truck made a huge difference. Also, gutting the EBPV and replacing the stock turbo wheel also made a big difference. When you do all that, replace the original boots on the turbo manifold y-pipe. Anything you can do to "contain" and "create" pressure (for boost and power), the better off you are. Put in a larger exhaust and a tymar-style intake, and you're making even more headway.
Though I've upgraded my TV for towing my 5er, back when I used my 7.3L PSD for this purpose, it was more than adequate for the OP's purpose. I can maintain 4th (OD) at 65 MPH on generally flat or moderately hilly terrain and was never disappointed to back down to 55 MPH in 3rd gear when in the mountains. Keep in mind that I tow a lot of big trailers for my business and since business is good I could easily justify the upgrade. Otherwise, I'd still be using my OBS 7.3L PSD for RV tow duties.
