I've never run the Eddies out of the box but IIRC they flow around 235-ish at .500. You can pick up 15 cfm pretty easy just fixing the VJ, bowl blending and opening up the pushrod pinch....well worth the work for another 20-ish hp and higher peak power RPM IMO. Edelbrock is notorious for tight guides so I do this as a matter of course anyway.

If the manifold outflows the intake port by a wide margin (let's say more than 10%) you're never going to realize it's full potential (as Brian I believe eludes to) and often the intake will get blamed for the mis-match. The M1 (strip dominator clone that it is) flows about 285 and is very balanced runner to runner and has decent taper and an agressive approach angle from the Plenum...arguably BETTER in many ways than the Larger Victor. As said the RPM simply doesn't have enough cross section where the four main branches split to its individual runner pairs to make big power upstairs ON a DEEP BREATHER motor, but it probably keeps up with the OOTB eddie just fine.

Again on ALCOHOL I'd want a larger straighter runner because you have to push more fuel (bigger jets) through the carb to the valves....Liquid fuel takes up space and alcohol takes more room than Gas (petroleum)...if you think about that that leaves LESS room for the air and you need both to make power. As Wade said torque will improve with the alcohol 9it always has in my experience) so the Perf RPM's upper bottom-mid range advantage is going to be offset by the broader torque curve and the smaller cross sections will very likely choke off the big end power of a 390 incher.

A small bore long stroke (3.94 x 4)combo is gonna make torque with any manifold....you could put a torker on an 8:1 455 Olds Vista Cruiser (4.125 x 4.25) and still pull a 32 foot travel trailer! But with the Strip dom/m1 you do have to watch the powerband, especially with an automatic, a high RPM single plane can and will fall out of the 'sweet spot' if you don't have enough flash to cover the wide gear spreads vs a 4 speed.

I've never run a victor on a stroker motor but ran a few W2 versions that were like a light switch in terms of powerband...all of it upstairs! Wouldn't fall out of a tree below about 4200 on my old 4 speed car but came on like a nitrous shot above that! Had to keep the revs way up to keep it in the happy zone for sure. But it'd probably work real well on a 416 incher with good heads and 3400+ stall.