Only time I had issues with the lines was when swapping out engines in a 76 Nova, different thread pattern in the older pumps, so the lines had that thread pattern and the new engine with pump was a metric I believe. The conversion I did on my '86 dually wasn't too difficult, I did swap out reservoirs though, using the one it came with.
The alternator was a tad different to figure out, but with enough research, I did get it to work without special adapters and resistors.