When one bumps up a 5.9 from the basic 160hp to 190hp, what is involved? I've been told it's a matter of doing something with the fuel pump. Does anything beyond 190hp require different manifolds, fuel pumps, turbos etc? The stock manifold went through three redesigns since the early 90's and I wondered if the newer/better design could be used for upgrades beyond 190hp. Also, the Allison 542 can handle the 190hp but would one have to go to a 5-speed with more hp capacity if you went to 230hp?

Jim & Tere
Save your money. There is no place in the hills of Tennessee that your 160 won't take you. From I-40 south on Rt 111 to Soddy Daisy is a thrill ride down hill and you might drop down to 42/45 mph going up hill but you will enjoy the view. You will be a little slower getting out of the gate at traffic lights, but it ticks off the cars behind you. However, this gives you a chance to blow your air horns as they pass you and scare the #&*$ out of them.(Did this many times during my tenure in Cookeville,TN)..................

The 542 is good for about 235HP. You need to change injectors to get there. Not sure of the difference between a 160 and 190hp. Might just need to change fuel plates in the pump. If you change plates change to a #11. You can also move the fuel plate for more power.

Gary if you have a chance is this the part you are referring to. http://www.xtremediesel.com/bd...jo77ACFc1k7Aod5EMBww
would you need a "pump shop" to install it?
Thanks
Wayne

That's the part, but mine is a Cummins plate.

Pretty easy to install. Remove the top of the pump and you will see it. Scribe the pump so you know exactly where the old one was (it is slotted).

Then remove and replace.

Later you can play with moving it.

In their instruction sheet they talk about a break off screw. Was there one on your pump (mine is not at home right now so I can't see it. Did Cummins call it a #11 Fuel plate?
Thanks again
Wayne

Replace the breakoff screw.

Unless the memory is failing again, I believe the fuel plate was stamped with an 11

I chose a conservative #11 cam plate (throttle guide/stop plate) for my 6BTA5.9
got a knock-off for under $30
http://www.ebay.com/itm/180680...p=mtr#ht_3560wt_1002
Did not need a pump shop to put it on, just my local Complete Truck Repair, who has done good work very reasonable for me.
Performance was not better. You really need bigger injectors for a lot more power. But, then you are going to stress the Ally.