Is there a difference in size between half ton pickup trucks and three quarter ton pickup trucks?
What is the difference between a S10 Chevy pickup and a C10 Chevy pickup Will a S10 Chilton book work for a C10?
Yes, even though you do not specify the front or rear bumper, both will fit. All d21 Nissan pickup trucks are referred to as "hardbody". They were manufactured, in the U.S., between 1986 and 1997. Most parts are interchangeable between the years, the only real difference is the bed length between the standard cab and extra cab, they are not interchangeable.
More than could possibly be given here. First you need to decide what you will be doing with it: light duty (quarter ton), standard duty (half ton), heavy duty (one ton), etc. If you will be towing a trailer with it and the weight of that trailer. Many other factors will affect your selection. Most vehicle manufacturers offer various models of pickup trucks.
Both of them are serial interface ports, but the protocol, connectors, bit rate and just about everything else is different. It's kind of like asking what's the difference between a Chevy and a Ford pickup: they're both trucks and they work approximately the same way, but that doesn't mean you can take parts from one and install them on the other with no problems because the details are different.