[Rocjeeper]

Personaly I would do a compression test on the current engine first. If that proves the engine is in reasonable mechanical condition, I would not replace the engine. I have heard more knocking 258 than non knocking ones, but those engines run for a long time. I would do the Howell fuel injection kit first. After all, if the egnine does come apart you can transfer everything over to the next engine. That stock carburetor is the father of all driveability problems, and the vacuum line spaghetti under the hood must be perfectly sealed and no cracks, along with all the electrical emission stuff working. My $.02