It isn't the injectors which make a lot of noise in your present vehicle, it's the shuttle.
All late model diesels now use common rail, electronic injection, and VERY high pressure fuel pumps. Although the tend to be RFI noisy, proper bonding will abate most of it.
The most important parts are the hood, exhaust system, and bed of the truck to the frame, and the bed to the cabin.
The next questions is, where are you going to mount the antenna, as that has some effect on the perceived noise level?
Last, peruse my web site for ideas.