Toyota 4Runner Forum : “Why would a 1992 4Runner have a miss?”

Why would a 1992 4Runner have a miss?

I just replaced the original motor with a rebuilt V6 3.0L engine. The engine runs really strong. It has been sitting for about four months while the engine was rebuilt, and replaced, etc. When we finally got it up and running and reconnected and it has an incredibly loud miss. You can hear it all the way back in the house. We tried replacing the distributor cap but it didn't change anything. I'm looking for any causes or ideas anyone has on ways to remedy this. I really need help FAST! Thanks in advance