Jeep Wagoneer Project??

[Skools Out]

Who out there has ever messed with one of these Grand Wagoneers that had a Straight 6 in it? I bought a 1985 awhile back as my Project for $200 as a boat puller to leave at the coast. It actually has no rust and runs just not to good and has a straight 6 4.2 in it. The problem is the motor when it runs a for a few it starts to smoke oil heavy. Well i was going to rebuild it but my neighbors 1992 Jeep Cherokee caught fire under the hood but they got it out quickly. Motor still turns over and has great compression. But it's a Straight 6 4.0 HO. So i ask him what he wanted for it. He said give him a $100 and he'd be happy. Will this motor fit in the place of my 4.2 without any issues? I've just got to get a carb intake that will fit the 4.0 *is it right?