I would build a good bottom end with a set of flat tops level with the deck.
id build that bottom end with main studs and wavelock rod bolts
id balance the bejeezus out of it crank and balancer, rods end to end, rod pin and piston weight if i had the option id choose the best set of 8 rods out of 2 motors small end in the middle of the small end casting etc not the gnarly looking, wonky 2 you find in each set
id use the King bearings race bearings
id do all the core/freeze plugs
i'd build it with clearances in middle of the tolerance
Id get a good harmonic balancer a known brand
id get a romac timing set, IWIS roller chain, a timing set where i can trust that the keyways and dots will be where they should be....! with some of the other big names you can't
i might..... put in a windage tray or a crank scraper
id match port my oil pump to the block
i'd make sure my pickup was solid
id put in a sump baffle
id measure exactly the required quantity of oil into that sump and make sure my dip stick read just below max. pull out and re site the dipstick tube if necessary
i'd have a new water pump
i'd bluprint my stock oil pump
new piston and relief spring
new senders
i'd paint it nicely
id tumble and clean up the chrysler hardware the screws with the "lead into the threads" so putting on sump and fuel pump is easy
id get either a rebuilder orginal carter pump and rebuild it or a new carter pump
changing the rod bolts means you have to have the rods resized and checked...
studs and rod bolts torqued to ARP spec not standard bolt spec
id run a clutch fan and standard alternator. its too easy to buy a **** electric fan set up
Id bolt on the 318 heads and a 4bbl inlet
id use the cast iron exhaust manifolds and id merge the collectors way back
id put in a standard dizzy and cheap HEI set up i.e mid 70s chevy 6 truck coil + and napa hei module
dizzy will potentially need a recurve
and see how it goes
the small valve 318 heads combined with the higher CR from the zero deck pistons and a small 600cfm carb will give you a wide torque curve that is just gooood fun around town...
once this is done you can do what ya like with cam heads inlet in future
and you can plan and save all while driving the car, cruising and going to shows
short block done ready for its next upgrade is a good place to be
and you have a benchmark to measure your upgrades against
what does good look like and what is better.... if you don't know you can't assign a bang for buck value to your upgrades
dave