well, now you done it.
it will be lighter and easier to handle with parts missing, lol.
are you gonna wait and see what your new friend says before you pull more off?
if it comes down to it and some machining will be done, I would imagine the machinist will want the pistons/rods out of the way so the head will need to come off, crank, cam and lifters out etc. if that is the case, and you are the engine guy, remove the head bolts in the same order you would do it if you were torquing up the head bolts. that can help eliminate the head warping. use some short lengths of rubber hose over the con rod bolts so as not to damage the crank if they rattle past a journal on their way out.you might as well get ready by making a few fixtures to keep everything in order. I use a length of 2x2 or 2x4 with some large holes drill into it for holding the lifters. mark the front with a screw, or something other than a felt marker, as the oil will make that go away or at least hard to read. smooth the edges etc so no sawdust gets in the engine on assembly. something to hold the pushrods as well, same deal with marking them to keep in order front to rear. some will say it doesn't matter for pushrods but hey, why not, they have wear surfaces like anything else so might as well keep the mating parts together, top to top, bottom to bottom. a box with dividers, like a tough version of a wine box has, works well for pistons to sit into. make sure to mark the orientation of the pistons (if not already, it was rebuilt so they should be marked) and keep the rod bearing caps matched to their rods and also their orientation to the rod (the divets in the ends of the rod bearings are on the same side), these should also have marks from the rebuilder. an old coffee can with some small holes punched into the bottom works well for holding all the bolts. I usually have a bucket for top end bolts and one for bottom end bolts. make sure the holes are smaller than the smallest bolt so nothing falls through, I use a small nail but a drill also works if you have the time. spray the bucket parts with your cleaner of choice, use a parts washing brush, paint brush or whatever to agitate and remove oil or other dirt, allow to sit for awhile, then spray off and dry. I usually use hot water and then blow dry as good as possible while still in the can, then spray liberally with wd40 to stop corrosion. a larger bucket of cleaner can be used to submerge the smaller bucket of parts for soaking.
make sure to be very careful with any engine bearing as cleaners can react with the bearing material. dish or laundry soap is a go-to for a lot of home rebuild guys. mark the bearings top and bottom on the back side or place them in a holder that is marker, like an egg crate, so the related parts can be cleaned properly before assembly. the bearing shell and the con rod/cap or engine block/cap need to be properly cleaned because a small particle makes a dent in the shell and then.....not good.
for buffing up the gasket surfaces the roloc style surface conditioning discs work well
https://www.amazon.ca/Scotch-Brite-0.../dp/B0002STR8Q
if pulling the engine and leaving the trans in the truck beware that the torque tube/rear of trans needs to be supported so it doesn't drop and cause damage to itself.
take pics before you dissassemble so when it is assembly time you can "remember" how things were