Mopar made the 6 quart low profile oil pan for the 1970/1971 Hemi and six pack 440 motors for both the B and E bodies, that pan works great on the street
Summit sells them (part # SUM G-3511 ) but don't use their 3/8 oil pickup
I'm working on finding the proper Melling oil pick now for those pans, once I find out which one works the best, either barely touches or almost touches the bottom of the pan installed with the windage tray, I'll add the part number on here
As far as rocker arms you get what you pay for, if your lucky
When I first started racing B and RB Mopars we had to buy and use adjustable pushrods
Now the choices for rocker adjustable arms are unlimited on type, price and quality
On the used factory stamp steel rocker arms I've never seen or held any that weren't loose on the shafts, never