Had a small cam Cummins years ago, I think the CPL was 0107 but not sure anyway it was a 420. Number one piston Split in half trash the motor, had a 290 in a wrecked truck outback took everything off the 420 put it on the 290 ran great for two more years. Never had any crank trouble but don’t know how much horse power it was turning out!
What's the compression ratio on the 290s? Guys building big hp are using 14 to 1 or 14.5 to 1 not sure on cpl maybe @OLDSKOOLERnWV can point you the right direction
Couple of things... A lot of wisdom has been spoken here. If you leave it as it is that engine may live on for quite some time. The 290 Cummins had a high compression ratio. I would have to check my books for the exact ratio but I bet it's around 17 to 1. You are very limited by that. All of the four hundred and above horsepower engines have 14 to 1 Pistons. I think some have 13 and 1/2 to 1. Too much fuel is not a good idea with a compression ratio that high. If you just add fuel pressure on to the pump without changing to oversize injectors and flowing the pump to those injectors you will most likely wipe the camshaft out. If you add fuel your timing really should be changed. Not to mention the turbo. You can have someone turn the pump up 10% or something like that but beyond that my own personal opinion is you are going to shorten the life of that engine. How much horsepower are you looking for?