I have a 1990 chevy truck

What engines and are they fuel injected or throttle body injection?

87 was a half year, if it is already tbi in the 87 then it will swap right over. If not you will either need to transfer your tbi and intake over or run a carbed 1990 chevy. I am assuming the engines are both the same size, you could have a 4.3, 305 or 350 in either of them. And to mrnewlan, tbi is fuel injection.