cash68

Okay, I have a 20' Sleekcraft Aristocrat Twin Tunnel, headers, bunch of bolt ons, etc. I want a polished intake, right now I have a Weiand Xcelerator intake, and I top out around 60mph at 4300-4400rpm, running a Mirage 21".

My ultimate goal is to get heads and an intake on this thing, along with an Alpha SS drive, which I hear is a direct bolt on 5-7mph. Knowing my overall plan... would you go for a polished single plane/high rise intake, or stick to a dual plane intake?

What makes this tricky is that I don't think Alphas like much over 4500rpm for very long. So maybe run a steeper prop, then try to get the RPMs back to where I am now?

But with that operating limit, at 4300rpm, is the advantage still the dual plane? Or single? I know singles come alive above 5000rpms, but with newer heads I'm wondering how that plays into things. Stock heads for now, but looking to upgrade.

SB

iTrader: (1)

Alpha’s are fine with rpm. They are nit fine (like most drives) fine with being toque loaded at lower rpm.
btw: a 269hp merc 5.7 usually likes 4600-4800 rpm at WOT.

Lots of guys here, and elsewhere, with Alpha’s run high 5,000 rpns and several mid 6’s. I beat the crap out iof mine (holeshots) and bring to 5600rpm to 6200 rpm depending on prop I put on for the conditions.

I don’t suggest the hole shots as that is how you break them easier. Soeakingbof which, the easiest and most gursnteed way to break them is shifting , say over 800rpm. Only tsjes a few shifts over 1k and crunch, crunch.

Edelbrock makes most of their manifolds with Eendurashine.
Professional Products (chinese) offers most of their intakes polished. Typhoon and Crosswind.

Stay with a high rise dual plane intake with those cubic inches. Edelbrock RPM and Air Gap RPM is what all others strive to be.