Brainstorming Ideas for 400-450 hp 360 Build

Preach it brother!
Just what you have stated has been the no brainer for decades and the build must be done for the situation at hand.

I say it often when speaking on my builds. There all in the street. Zero deck flat tops with a good quench w/ closed cha. Seed heads eating pump gas. Great performers all around.

On a race build going nutz, that open chamber is what I’m eye balling! Or opening up the closed chamber to de-shroud the valves as much as possible. Gotta get it to breath and allow that fuel to spread around.

Get the best high flowing head you can afford!

I've said several times you can make more HP with the open chamber head for the reasons MO mentions
especially you keep the revs above the torque peak
and
run extra special good gas
The traditional high compression big cam combination converter, gears etc

but you can make a better running street build with less sensitivity to timing and fuel with tight quench
remember this is a 4 speed build
no converter to keep the revs up and more likely to ping if lugged
build the tight quench motor
you do not want to always have to shift down when you would rather just give it some gas and go