"Aluminum" gets a bad rap. nothing wrong with aluminum rockers if they are quality pieces. 7075 T6 grade would be the premium pieces
I have run both needle bearing and bushed with success on other applications, the needle bearing units MUST be on a matching hardened shaft to work and last properly.
A while back while wandering the pits before an IHRA pro stock event early in the AM i had the opportunity to speak with Tony Jones who was the carb guy for the Goforth team.
I asked him about his split dominators sitting on the plywood spacers. he told me it was the best insulator he had...
MY.02: Stock rods with new bolts. if you can get a light weight aftermarket piston and then balance the assembly (this is the money you would have spent on aftermarket rods)
you are way ahead. the lighter piston takes a huge amount of load off the rod, Plus Mopar rods were very good pieces.
I got a "free" Motorhome with a premium package 413 ( industrial top end ) gave it to a friend who was doing vintage stock car stuff.
he switched the top dress over to regular automotive and it is a sweet running big block . FWIW it weighrd in at a tick over 1k lbs with the industrial parts on it!
If you do your math correctly with master cyl displacement and pedal ratio , manual brakes will stop it fine.
There are several on line calculators to help. 180 MPH road coarse cars do not use power assist.
Get a real temp reading..
And I'll be that guy , please be careful, we had an upper rad hose blow off an overheated car my dad and I worked on ( without a proper temp gauge)
and it cooked him from the waist up like a lobster.
Ive had good luck with Cronatron NI rod for cast repair, it doesn't weld great out of position but that's not an issue in this case.
or braze it , easy peasy either way , not the end of the world.