Try someplace like this...
From a CAT site re: the C7 engine and it's injectors...
Improved HEUI Fuel Injectors
The Cat C7 has proven high-pressure, direct injection fuel system electronically monitors operator demands and sensors optimize engine performance.
Hydraulically actuated electronic fuel injection (or HEUI™) is a Caterpillar-exclusive technology with a proven track record built by millions of engine hours. The refined HEUI design delivers multiple microbursts of fuel during the engine's compression stroke, precisely regulating the combustion cycle. The improved HEUI design also enhances combustion and "rate shaping"¯ of fuel delivery, which helps control engine sound and vibration levels. The HEUI system continues to offer excellent reliability because it has fewer moving parts than mechanical unit injection and requires very few adjustments, reducing maintenance costs and increasing machine availability.
Here is a link to a description of the C7 setup from an off-road CAT equipment site but I suspect it is similar if not exactly the same engine.
...and yet another blurb about the CAT HEUI injection system
HEUI™ Fuel Injection System
"¢ HEUI fuel system fully integrated with ADEM
"¢ Cross-flow cylinder head with integral fuel and oil
manifolds "” completely rebuildable
"¢ Improved cold startability (down to 0? F) "” with
standard air inlet heater
"¢ Caterpillar designed combustion technology and
performance criteria for superior fuel economy and
greater performance over a wider operating range
"¢ Higher injection pressures for better fuel economy
and performance while meeting latest emissions
"¢ Adjustment-free HEUI fuel injector with stainless
steel sleeve for greater reliability
"¢ HEUI oil rail integrated into cylinder head provides
high-pressure oil to power the HEUI injectors
Per Johnson CAT, they are about $450 each
Their number is (951)683-5960. I realize you are in MN but maybe give a call to your local CAT dealer. Johnson is a HD machinery dealer but they also have a truck division/shop on site to deal with on-the-road rigs including MH's. You should first bring it to a shop so they can put it "on a scope" and diagnose the source of the miss before you shell out that kind of $$$.
Just my $.02 Pesos