If your engine bay is scratched and just wont clean up then yes it is worth the extra work. Reinstalling the engine is not really a problem either if you are careful.I have installed my engine twice now since my engine bay was painted and have not scratched anything so it can be done. Once the engine is out the bay will need a thorough cleaning and degreasing .Once it is clean there are alot of parts that will have to be removed so take lots of digital photos of every corner of your engine bay for future referrals when reinstalling everything. You really only need to paint from the box rails up , so everything under the rails can be masked off.
