Is there a difference between a n/a IP & a turbo IP??

[CapnSass]

To get my 84 245 d24 up & running, the injection pump needs to be rebuilt/replaced/???
I want to eventually (sooner than later) convert to a turbo. Is there a difference between injection pumps?? So if I pay for the rebuild now, will I need to pay again during the conversion??
Can anyone offer a better idea than a rebuild? I've had trouble finding a replacement and am looking at the rebuild, which is just under $1000.
Thanks for any an all input.