Late-gen MDS setups close the valves on deactivated cylinders to "turn them off", so you probably don't have any ring trouble.
I find it easier to pull the head and manifolds as a piece, but I'm a big guy and have an engine crane handy as well. The manifold gasket, if it needs to be serviced, is done on the bench.
Check the cylinder head screws before you start work - if they're not painted, get some bright colour of paint (I typically use yellow or red.) If they're painted, order a new set. The 242ci head screws (per FSM) may only be fully torqued twice - they're a modification of the old Torque-To-Yield (TTY) head screws used on Diesels. Yes, they can and do fail (rupture) if you try to torque them a third time - I've made a decent amount of money burning them out of blocks sitting in place...
Replace the exhaust & manifold hardware with bronze (best - check marine supply houses) or SAE5 carbon steel. Don't bother with CRES - it's not enough to help - and SAE8 loses strength faster than SAE5 due to heat cycles - it won't be long before the SAE8 is actually weaker than SAE5!
Undercar, like on the clamps and flange hardware, use marine brass. It won't corrode or seize, so it will be easier to remove next time!
Make a "thread chaser" out of a hardware store-bought SAE8 1/2"-13 x 3" screw by cutting two or three longwise flutes down the side. Run it down the hole and back out to clean the crappola out - clean off the screw and repeat through all fourteen holes.
NB: The #11 cylinder head screw hole (driver's side front) extends into the coolant jacket - be sure to coat the threads on this screw with something like LocTite PST, plumber's PTFE pipe dope, or RTV. Treat This Point As Important. (I've used the first two with good results. There's no reason the third shouldn't work - I just haven't used it yet.)
Manifold hardware gets LocTite #272 (or equivalent) or don't bother. It's not tight enough to require never-seez, and other grades of chemical threadlocker will break down due to heat. Replacement studs may be made using 3/8"-16 brass threaded rod (cut to 2-1/4" long,) and replacement screws should be 3/8"-16x1-1/4". Retain the dish-shaped washers and reuse them. If you can't get 1-1/4" long screws, get 1-1/2" long and a bag of flat washers - take up the slack by using flat washers between the screw head and the bowl washer.
Torque specs for just about everything should be on my site in the Tech Archives - taken from FSM. If I don't have your year (yet...) pick a year close to yours.