What would you build if limited to 372ci - with boost as an option

If you didn't like my idea of the r block, a destroked hemi would be a great idea. They actually use to race this combo.
The up front cost of the R motor is my only worries there. Looking at options that can be put together. I have a 383. 400 and 360mag at home. The thoughts of BBC rods (cheap and strong), a reground crank, etc feels more possible (not that it is in the grand scheme).