1989 D-250 Mods
 

Hi guys,
I am looking for some solid advice to clear up some misconceptions I have. To begin, I am planning on putting a 4" Diamond Eye trubo back exhaust on my truck. I would also like to remove the stock injection pump spring and replace it with a 3200 rpm spring. Fixing the KDP is also on the list. With my truck having the stock 727 tranny, would either of these things reak havoc on the stock transmission? Also, do you think that guages would be necessary to monitor any changes that these things could create? Any other things to watch for or consider would also be helpful.https://www.dieseltruckresource.com/...cons/icon7.gif

As long as your tranny is in good working order right now, those mods won't kill it. A good converter and shift kit will do wonders for the truck though. I recommend gauges so you can tell what each mod is doing for your truck. They'll help alot with tuning and keep you from messing something up if you start modding it even more. :cool:

From what I've garnered on this site...it's the torque converters that are the weakest link on the auto's. The 727 is a plenty stout tranny.

But gauges first, Tach, Pyro and Boost to start, with will give you enough info to keep things happy.

Nice truck by the way, 84k on the clock is amazing!

First mod on a Cummins should always be to kill the KDP.

Second mod should be boost, pyro, and on an auto, trans temp.

Once those goodies are in place, you'll be set to turn up the pump and have some fun.

Yeah, I have learned about the KDP through the forum and Diesel Power Magazine. I tried to get into the KDP section of the sticky but was not able to open the link. However, where exactly is the KDP located and what does the actual Dowel pin do? Is it hard to replace?

Thanks for the compliment stillsmokin. I love the truck and want to just get a little more power through the exhaust and 366 spring. I am not looking to do anything outrageous with it yet as tech school in the future has me working under a budget.

The KDP is located inside the gear/timing case at the front of the motor. It's only use was during assembly for alignment of the gear/timing case to the block.

When you tab the KDP, be sure to pull out and loctite all the case bolts as well. Those have been known to come loose and fall out as well causing damage equal to what the KDP does.

Hmmm.... That's interesting. I learn something new every day from you guys.

Thanks.

Good advice. I will add fuel pressure gauge after the fuel filter to keep the VE happy.