with stock governer springs and 4.10 gears youre not gonna see much as far as speed. Unless you tow quite a bit, I would recommened switching over to 3.55 gears. At the very least put in a 4k GSK kit, itll help your top end out considerably.

 

have you cleaned out the screen on the fuel bowl on the bottom of the fuel heater assembly by your lift pump, ( commonly overlooked and get plugged off with garabage )also check fuel pressure, anything over 15 plus is good, if it's low check your fuel relief valve and or up grade it to a 35 psi valve,( mine had that problem, i almost got out and shot it one day to put it out of my misery ) and last but not least make sure your lift pump is in good shape, most of them only last bout 100,000 miles or so, if you need a heavier pressure relief valve replace your fuel filter with one that does not have the drain on the bottom cuz they will got to leaking with the higher pressure, i was running 30 plus boost on my hx35 with stock 180 injectors pulling a hill before i did my tear down, and could bury the speedo with a 3k spring kit with 3:55 gears, and a hopped up tranny,, good luck bud hope this helps,

 

When i still had 3.54's i hit 112 mph with my 40's. didnt know she could do that. but it was scary. I would definetly check your fuel pressure and get a gsk when you can.

 

where is the test port for checking fuel pressure on these things? will my regular fuel pressure tester kit that i use on my gaser work?

 

if you go with higher gears like a 3.54, get a smaller tire for sure or itll bog down, as far as power goes you have the most universal platform for power. diesel power just made about 250hp and 670ft lbs at the wheels with next to free mods with a 12v!

 

im leaving the gears alone, just gonna save my pennies for the 4k spring and valve springs and im gonna go ahead and check my fuel pressure. for now iv got other problems to deal with, i brought my trucks out to do some truck pulls tonight and snapped something in the front diff... the chevy held together all night and the cummins let me down, kind of surprising really. i dont think my issues with no top end are from a slipping clutch because i worked my clutch hard tonight and the truck didnt get any slower, actually drove home just as good as always.

 

You will be very happy with the 4k,just going to have to keep an eye on the pyro after. a turbo will soon follow most likely then she will really pull hard

 

I'd leave the 4.10's in there running 35's. I believe 2800 rpm is the max governed rpm's for your engine and being bone stock, it's definitely not going to be a rocket ship. Be sure you are getting full fuel flow/pressure to the lift and injection pumps, perform a couple free mods and throw in the 4000 rpm springs and it will seem like an entirely different truck!

The chevy didn't break anything 'cause it's only making half the torque as the Cummins .

P.S. The Cummins didn't let you down. The Dodge did. There's a difference.

 

Mine used to react the same way... pedal almost all the way to the floor and nothing left to pass with. Turned out my injectors were on their way out, then the VE pump gave up the ghost. Now with a rebuilt 32k rpm pump & POD 300 +55 injectors it flys with a minimal amount of right foot and will run out to 180km/hr !

 

For him I think its simply a result of 4.10 gears with stock gov springs. By the time the truck is hitting 75-80 mph, its probably already starting to defuel.