83 ranger need help fast

[Big Jim M]

Ranger danger you need to help us out a bit here

It b4 swap it was a 3 cylinder lol and still made it up rainier hill then i installed fresh motor ran great for 500 miles then i was headed back up said hill and it slowed to a stop it was fine then all of a sudden its worse the b4 the swap ive replaced the carb, plugs ,wires, dist. Cap ,timing belt, tensioner

After you did all these changes did it go up the hill? If yes then there is something that has gone wrong since it ran good. If no then we will look at the things you changed to ascertain whether or not you did something wrong.
Big Jim