prepping magnum

Looks like it could use at least one new valve cover gasket! ;)

You'll need to change the oil pan over to a center sump, I believe the Durango's were rear sump and that won't fit our cars, so you'll need a new oil pan gasket. If you're changing the intake over to a carb you'll obviously need intake gaskets too. The Durango exhaust manifolds may not work with your set up either (the driver's side won't clear power steering IIRC), so a set of exhaust manifold gaskets are probably in order.

How many miles are on it? If its over 50k, I would probably change out the timing chain for a nice double roller now while its out of the car, just easier than doing it later.

So, if you do all of that - intake and exhaust manifold gaskets, timing cover and water pump gaskets, oil pan gasket. And that valve cover gasket. So really, the only gaskets you're probably not changing are the head gaskets.