Not much problem, just a different set of mods. Turbo needs to be replaced, injectors, a box or programmer needs to be used, air filter upgraded, and an auto transmission needs to be seriously beefed up. If manual, a good clutch needs to be installed. One characteristic of 12v's is that they tend to produce more torque compared to hp than later engines. Put another way, if you get a certain amount of torque from both a 12v and a common rail motor, the common rail motor will probably be making more top end hp. That's largely a function of the fact that all '99 and later 5.9 cummins in dodge trucks have 24v heads. This gives them more airflow and consequently raises hp. 12v heads can be ported to help considerably, which my engine will get at some point.
Perhaps the single saving grace of the '94-'98 12v 5.9 is the bosch p7100 pump. This is THE injection pump to have if you want to make lots of power with the 5.9. The bosch cp3 is catching up, but it requires TWO of them to do it. One in the stock location and one belt driven. The p-pump is so good that people have actually taken '03 and later common rail engines and custom made timing covers to adapt a p pump to them! Especially modified, a p pump can flat PUT THE FUEL TO IT. Wanna make 1000 hp or more at the wheels? Don't fuck around with some dumb shit, get a modded p pump, firehose injectors, a bunch of turbo, and let it ride. Wanna spin the motor to or past 5000 rpm? No problem-put a set of sufficiently stiff governor springs in it.
Any of you guys seen Gale Banks brag about spinning his highly-modified duramax to 5k+? Folks have been spinning STOCK BOTTOM END 5.9 cummins well past 4k for YEARS, with 5k being a set of mainstuds away. I STILL don't understand that dumb shit-he acts like he's invented the wheel, but people have been doing it practically forever with a motor that ought not be able to. The stroke on a 5.9 is 4.72 inches. The pistons and rods AREN'T EXACTLY LIGHT. Think a 440 rod and piston combo is heavy? Nah chief, it isn't. But old Gale is god. Ok.
Anyway, you can make dumb power with any of the variations of the 5.9 put in a dodge truck-the method and potential max power just varies.