Small notch needs to be taken out of the Block for the Rod Bolts other then that it's really nothing more then a .30 over bore. Crank and Pistons is really all that changes. Stock rods are fine. You can find kits everywhere just do a search on "Mopar Stroker" and you will find them.

5.9 vs 360 5.9 has Roller Cam if you want to do a Roller, I only know of 4 Shelf Roller Cams from MOPAR right now. If they don't meet your need then you can have your "Core" reground. You will need to replace the stock push rods if you do that since they will be short.

If you decide on 5.9 you have to make a few more decisions. 5.9's did not come with Mech Fuel pumps so the "Stock Roller Cam" does not have an eccentric to drive it. Also the 5.9 Timing Chain cover does not have provisions for one. This really isn't an issue since you can either get an adapter or 2 of the MOPAR Roller Cams have eccentrics. For the Timing Chain Cover the 360's will work.

Oil Pan on the 360's and 5.9's will exchange but finding one for a Car "Center Pump" in a junk yard is rare, 98% of these engines were in trucks and vans.

5.9 stock head's while not the best in the world do flow better then 360's only due to the newer design, but they have a tendency to crack between the valves. 5,9's use pedistal Rockers vice the Shaft Rockers. Just something else you need to consider There are alot of options for Replacement heads if you need them.