To put a gen II 5.0L drivetrain into your Gen I truck the wiring is going to be up to you
there are a few trucks I know of running around with this conversion, mine and MoabB2's are two examples of this conversion.
the wiring can be a bit tricky, but its not impossible
have you ever done anything like this before?
You would have to modify the 97 5.0L engine and computer harness heavily to mate it to your truck and have everything working correctly, including the transmission
the 1997 engine mounts will not work in your Gen I frame
There are a few basics to putting a 5.0L in your gen I, first you must re-locate the oil filter, second you will need a dual sump oil pan and pickup tube, you should consider the torque monster conversion headers, and stuffing a radiator in front of your engine will be fun
I spent $6500 and 6 months doing my conversion, and I have done several conversions prior including wiring...I did 99% of the work myself (sans exhaust) I know Moabb2 had his truck in 3-4 different shops trying to get the conversion completed (read expensive headache)
it can go smooth or it can be headaches, your best bet is LOTS of research
my conversion thread is in my signature, TAKE NOTES