572 RB Street motor advice?

Mid 9's means you'll need a weight to power ratio of 4.5 in a good chassis. In a street chassis you might need more like a 4:1 ratio. So if the car is 3200 lb race ready (with driver) then you'll want at least 800 hp on tap.

An 800 hp pump gas engine that is street friendly is going to take some work. If it was me I'd use a 4.25 crank to keep the oiling internal so that gives you 540 inches which means you are shooting for 1.50 hp/inch. Not a crazy number to hit with a pump gas engine but everything has to be correct. You'll probably need a little more head than the TF 270 to hit 800 hp so perhaps the next step up would be one of the CNC version of the 440-1.

I'd use a professionally ported 440-3 intake with a 2000 cfm Holley throttle body and plumb the intake for port injection. Use a Holley dual sync distributor and you'll have a fully controllable EFI + ignition system. Not sure on the cam, I'd say a solid roller in the 260 or 270 range for duration and as much lift as you can afford. Maybe something in the 700 to 750 range for valve lift. Good thing about a big engine is you most likely won't be turning it much past 6500 rpm so the valve train will have a fighting chance. You'll need high quality rocker arms, springs and pushrods. Probably need to work with T&D and Manton.

Probably cost a solid $20K to $25K to build an engine like on top of the block that you already have. You'll want to work with a shop that has a bunch of experience with those types of engines since they'll be able to save you from the rookie mistakes. It still might take two or three tries to find the correct cam profile. A 2 inch to 2 1/8 header would probably work pretty well and you'll want at least a 3 inch exhaust if not a 3.5.

Good luck.