Hey all, new here... my first Mopar! Few questions

If you're not in a hurry, maybe you should start with the 318. Assemble and install it, gaining important knowledge and skills. Then you would have a car to drive while you make upgrades to the chassis, such as bigger torsion bars, capable differential, subframe connectors, and most importantly, brakes that will handle the weight and power of the big block. Then you could take your time building the 496 project engine, and have a safe car to put it in by and by. As Mick Jagger once said, "Time is on your side."