Stage V Hemi replacement head vs Custom head

[Budnicks]

Higher RPM you want to run the more camshaft & CFM flow you'll want
be a pouch without something like 5.13:1 gearing, even with a smaller 29.5 X 10.5w tire
even with a 5,500 stall, if you're not spinning it high-er, like 8,000+
where the Race Hemi Heads want to be, for drag racing,
albeit a stroked engine can use a bit more CFM down low,
too big of head will be 'somewhat lazy' down low under 6k
give up some bottom end too, but not as much as you'd think
unless you have a crapload of stall & steep gears...

not all combos work alike

I'm Stereotyping of course,
you can make stuff work with different combos

My altered with a 526cid Milodon Mastodon (a de-stroked 572) 1,000-ish HP N/A
11.5:1 with a 0.050" (killed some comp.) dead soft copper head-gasket, o-ringed
N/A Alcohol w/Enderle hat on an Eldelbrock tunnel ram, 180a Pump
nozzles down by the intake port entry, directed at the intake valve
heads 'only' flowed about 430cfm (intake, good for then)
int. 0.022''/exh. 0.020" lash, w/lash-caps, 0.790"-ish @ gvl,
roller w/1.60:1 Rocker Ratios, 305* advertised duration/Crane
(no idea what it was at 0.050" now)
old Mopar DC Alum heads/ported/single plug, 1980-82 era
needed or really wanted way more gear
I had 33"x 15" tire & a with a 4.88:1 rear gear,
it wanted way more, it was crossing the line at 9,900-ish RPM,
with 8% converter slip w/6,000 stall, & a trans-break, P/G
w/really tight top end lockup, stater
it wanted more gear
almost same combo, it was great blown @ 6.90s @ 190-ish (1,806 #s)
but not N/A FI on the tunnel-ram, 7.90 S/E it was great, easy on it too
but it wanted more gear & more compression
(granted an all out drag racing build, of that era & not pump gas stuff)
it wasn't even peaking at 9,900 at the stripe 4.88:1,
went to 10,400 later, with 5:13:1, converter slipping way more
but is hard on parts, trans got hot really fast too

granted you you're not trying to go 200 mph either
but;
500cfm isn't needed for what you're doing