Ok, now don't get me wrong here, because I say this with a grin, but I have to ask. Have you completely lost your freaking mind ??? You have a 79' Bronco, the 78/79's are pretty much the *ultimate* bronco setups having a solid V8, a *very* tough C6, an INDESTRUCTABLE NP205 *gear-driven* transfer case, a 9" rear axle and a D44 solid front axle. This is a combination that results in a toughness and durability that modern trucks can only *aspire* to match. The 78/79's pretty much set the standard, and you're looking to SWAP your existing straight axle D44 for what has to be either a D44IFS-HD or a D50 ?!?!?! Have you gotten off your medication ?
Swapping in the 460 is an excellent idea, but stop right there & sell the rest of it as a rolling chassis or maybe score the D60 rear end out of it and swap THAT into the Bronco, but changing a 79' over to an IFS front end is like putting a Yugo engine into your Ferrari. I can promise you right now you'll never hear the end of it at cruise-nights or on trail rides. You'll be the guy with the truck everyone's pointing at and giggling. If you've got a woody to swap axles then find a D60 front end from the junkyard, swap in the 460 & D60 rear from the free-to-you F250 and THEN you'll have yourself one badass Bronco, but right now you're going in the other direction.
78/79's don't have engine cradle's. I'm guessing that what you're looking at is the front crossmember. Regardless, a swap like that would involve *quite* a bit of work, cutting & fabricating. Even if there WERE some merit to the swap it would be a *whole* bunch of work. The frames are completely different, the IFS mounting points simply don't exist on the 79' and the whole job would pretty much consist of custom fabrication. The only axle you want to swap that D44 for is a D60.