oh boy 2003 e250 4.2l exhaust manifold studs in aluminum and rusted
 

so left exhaust manifold is cracked and trying to replace it . from the top it didn't look so bad underneath looks a lot worse. the metal studs are rusting away in the aluminum head and the damn dipstick is in the way of one nut along with probably having to get a new one because its rusted and then going into the block can be a nightmare. using heat on the aluminum I guess everyone would right? and how about if the studs snap off drilling out metal in an aluminum block? also that dipstick think heat is gonna be able to wiggle that thing out ?

There are a number of threads and how-to fixes/repairs for this very thing to be found in the V10 & V8 forums here on FTE.

Depending on your skill level and motivation its doable and sadly is a frequent thing on the Modular Motors.