ISX and Signature Interchange help

I'm in the process of building a 09 peterbilt 389 glider kit, it's spec'd out for a 2007 ISX. Would it be possible to put a Signature series motor in its place? The kit came with an engine harness, engine mounts, CAC tubes and intercooler. the cab is also pre wired for the 07 ISX. In the search for an engine I've come across a few Signature ISX engines for sale. Seems that the signature would be a better choice due to lack of EGR and a higher torque rating (in the market for 600HP models) although i understand some Signature motors did have some durability issues (crank failure, etc)
any help is greatly apreciated

 

Not sure, it was ordered by someone at the daelership, according to them, the person who ordered it put down a down payment and then they "got out of the buisness" and the deelership was stuck with it. The boss cut a deal with them when he purchased one of our new tractors, so i couldn't give ya an honest answer. Problem is that i have to piece it together how it was spec'd out.

 

I believe its VECU. I was going to put a C-16 in out of a rollover but i don't think the CAT electronics will work with the 389 cab and dash that was wired for a cummins. things like the throttle sensor and gauges wont work from what i understand. even so i dont know what it would be like adapting the cat engine harness to the firewall of a truck designed for a cummins

 

So basically i can use any engine i want its just a matter of re-pinning the conectoin at the firewall?
thanks for the help

 

Would a signature be a better choice for an engine? more straight foreward install than a Cat? how close is the signature to the isx? I see a lot of engines labeled as Signature ISX's,
i was under the impression that the ISX and Signature were two different engine's?